Add tests for change in Reference Records

These tests support the following normative change

"Normative: Allow null or undefined in Reference Records"
tc39/ecma262#2267

The tests concerning the `delete` operator increase coverage to verify
behavior which, though related, is not altered by the normative change.
These tests are intended to guard against regressions as engines
implement the new semantics.

test/language/expressions/assignment/target-member-computed-reference-null.js

@@ -0,0 +1,50 @@
+// Copyright (C) 2015 André Bargull. All rights reserved.
+// This code is governed by the BSD license found in the LICENSE file.
+
+/*---
+esid: sec-assignment-operators
+description: Assignment Operator evaluates the value prior validating a MemberExpression's reference (null)
+info: |
+  # 13.15.2 Runtime Semantics: Evaluation
+  AssignmentExpression : LeftHandSideExpression = AssignmentExpression
+
+  1. If LeftHandSideExpression is neither an ObjectLiteral nor an ArrayLiteral,
+     then
+     a. Let lref be the result of evaluating LeftHandSideExpression.
+     [...]
+     e. Perform ? PutValue(lref, rval).
+
+  # 6.2.4.5 PutValue ( V, W )
+
+  [...]
+  5. If IsPropertyReference(V) is true, then
+     a. Let baseObj be ? ToObject(V.[[Base]]).
+---*/
+
+function DummyError() { }
+
+assert.throws(DummyError, function() {
+  var base = null;
+  var prop = function() {
+    throw new DummyError();
+  };
+  var expr = function() {
+    $ERROR("right-hand side expression evaluated");
+  };
+
+  base[prop()] = expr();
+});
+
+assert.throws(DummyError, function() {
+  var base = null;
+  var prop = {
+    toString: function() {
+      $ERROR("property key evaluated");
+    }
+  };
+  var expr = function() {
+    throw new DummyError();
+  };
+
+  base[prop] = expr();
+});

test/language/expressions/assignment/target-member-computed-reference-undefined.js

@@ -0,0 +1,50 @@
+// Copyright (C) 2015 André Bargull. All rights reserved.
+// This code is governed by the BSD license found in the LICENSE file.
+
+/*---
+esid: sec-assignment-operators
+description: Assignment Operator evaluates the value prior validating a MemberExpression's reference (undefined)
+info: |
+  # 13.15.2 Runtime Semantics: Evaluation
+  AssignmentExpression : LeftHandSideExpression = AssignmentExpression
+
+  1. If LeftHandSideExpression is neither an ObjectLiteral nor an ArrayLiteral,
+     then
+     a. Let lref be the result of evaluating LeftHandSideExpression.
+     [...]
+     e. Perform ? PutValue(lref, rval).
+
+  # 6.2.4.5 PutValue ( V, W )
+
+  [...]
+  5. If IsPropertyReference(V) is true, then
+     a. Let baseObj be ? ToObject(V.[[Base]]).
+---*/
+
+function DummyError() { }
+
+assert.throws(DummyError, function() {
+  var base = undefined;
+  var prop = function() {
+    throw new DummyError();
+  };
+  var expr = function() {
+    $ERROR("right-hand side expression evaluated");
+  };
+
+  base[prop()] = expr();
+});
+
+assert.throws(DummyError, function() {
+  var base = undefined;
+  var prop = {
+    toString: function() {
+      $ERROR("property key evaluated");
+    }
+  };
+  var expr = function() {
+    throw new DummyError();
+  };
+
+  base[prop] = expr();
+});

test/language/expressions/assignment/target-member-identifier-reference-null.js

@@ -0,0 +1,31 @@
+// Copyright (C) 2021 the V8 project authors. All rights reserved.
+// This code is governed by the BSD license found in the LICENSE file.
+
+/*---
+esid: sec-assignment-operators
+description: Assignment Operator evaluates the value prior validating a MemberExpression's reference (null)
+info: |
+  # 13.15.2 Runtime Semantics: Evaluation
+  AssignmentExpression : LeftHandSideExpression = AssignmentExpression
+
+  1. If LeftHandSideExpression is neither an ObjectLiteral nor an ArrayLiteral,
+     then
+     a. Let lref be the result of evaluating LeftHandSideExpression.
+     [...]
+     e. Perform ? PutValue(lref, rval).
+
+  # 6.2.4.5 PutValue ( V, W )
+
+  [...]
+  5. If IsPropertyReference(V) is true, then
+     a. Let baseObj be ? ToObject(V.[[Base]]).
+---*/
+
+var count = 0;
+var base = null;
+
+assert.throws(TypeError, function() {
+  base.prop = count += 1;
+});
+
+assert.sameValue(count, 1);

test/language/expressions/assignment/target-member-identifier-reference-undefined.js

@@ -0,0 +1,31 @@
+// Copyright (C) 2021 the V8 project authors. All rights reserved.
+// This code is governed by the BSD license found in the LICENSE file.
+
+/*---
+esid: sec-assignment-operators
+description: Assignment Operator evaluates the value prior validating a MemberExpression's reference (undefined)
+info: |
+  # 13.15.2 Runtime Semantics: Evaluation
+  AssignmentExpression : LeftHandSideExpression = AssignmentExpression
+
+  1. If LeftHandSideExpression is neither an ObjectLiteral nor an ArrayLiteral,
+     then
+     a. Let lref be the result of evaluating LeftHandSideExpression.
+     [...]
+     e. Perform ? PutValue(lref, rval).
+
+  # 6.2.4.5 PutValue ( V, W )
+
+  [...]
+  5. If IsPropertyReference(V) is true, then
+     a. Let baseObj be ? ToObject(V.[[Base]]).
+---*/
+
+var count = 0;
+var base = undefined;
+
+assert.throws(TypeError, function() {
+  base.prop = count += 1;
+});
+
+assert.sameValue(count, 1);

test/language/expressions/assignment/target-super-computed-reference-null.js

@@ -0,0 +1,37 @@
+// Copyright (C) 2021 the V8 project authors. All rights reserved.
+// This code is governed by the BSD license found in the LICENSE file.
+
+/*---
+esid: sec-assignment-operators
+description: Assignment Operator evaluates the value prior validating a SuperProperty's reference (null)
+info: |
+  # 13.15.2 Runtime Semantics: Evaluation
+  AssignmentExpression : LeftHandSideExpression = AssignmentExpression
+
+  1. If LeftHandSideExpression is neither an ObjectLiteral nor an ArrayLiteral,
+     then
+     a. Let lref be the result of evaluating LeftHandSideExpression.
+     [...]
+     e. Perform ? PutValue(lref, rval).
+
+  # 6.2.4.5 PutValue ( V, W )
+
+  [...]
+  5. If IsPropertyReference(V) is true, then
+     a. Let baseObj be ? ToObject(V.[[Base]]).
+---*/
+
+var count = 0;
+class C {
+  static m() {
+    super[0] = count += 1;
+  }
+}
+
+Object.setPrototypeOf(C, null);
+
+assert.throws(TypeError, function() {
+  C.m();
+});
+
+assert.sameValue(count, 1);

test/language/expressions/assignment/target-super-identifier-reference-null.js

@@ -0,0 +1,37 @@
+// Copyright (C) 2021 the V8 project authors. All rights reserved.
+// This code is governed by the BSD license found in the LICENSE file.
+
+/*---
+esid: sec-assignment-operators
+description: Assignment Operator evaluates the value prior validating a SuperProperty's reference (null)
+info: |
+  # 13.15.2 Runtime Semantics: Evaluation
+  AssignmentExpression : LeftHandSideExpression = AssignmentExpression
+
+  1. If LeftHandSideExpression is neither an ObjectLiteral nor an ArrayLiteral,
+     then
+     a. Let lref be the result of evaluating LeftHandSideExpression.
+     [...]
+     e. Perform ? PutValue(lref, rval).
+
+  # 6.2.4.5 PutValue ( V, W )
+
+  [...]
+  5. If IsPropertyReference(V) is true, then
+     a. Let baseObj be ? ToObject(V.[[Base]]).
+---*/
+
+var count = 0;
+class C {
+  static m() {
+    super.x = count += 1;
+  }
+}
+
+Object.setPrototypeOf(C, null);
+
+assert.throws(TypeError, function() {
+  C.m();
+});
+
+assert.sameValue(count, 1);

test/language/expressions/delete/member-computed-reference-null.js

@@ -0,0 +1,21 @@
+// Copyright (C) 2021 the V8 project authors. All rights reserved.
+// This code is governed by the BSD license found in the LICENSE file.
+
+/*---
+esid: sec-delete-operator
+description: Delete Operator throws an error if the base reference is not object-coercible (null).
+info: |
+  # 12.5.3.2 Runtime Semantics: Evaluation
+  UnaryExpression : delete UnaryExpression
+
+  [...]
+  5. If IsPropertyReference(ref) is true, then
+     a. If IsSuperReference(ref) is true, throw a ReferenceError exception.
+     b. Let baseObj be ? ToObject(ref.[[Base]]).
+---*/
+
+var base = null;
+
+assert.throws(TypeError, function() {
+  delete base[0];
+});

test/language/expressions/delete/member-computed-reference-undefined.js

@@ -0,0 +1,21 @@
+// Copyright (C) 2021 the V8 project authors. All rights reserved.
+// This code is governed by the BSD license found in the LICENSE file.
+
+/*---
+esid: sec-delete-operator
+description: Delete Operator throws an error if the base reference is not object-coercible (undefined).
+info: |
+  # 12.5.3.2 Runtime Semantics: Evaluation
+  UnaryExpression : delete UnaryExpression
+
+  [...]
+  5. If IsPropertyReference(ref) is true, then
+     a. If IsSuperReference(ref) is true, throw a ReferenceError exception.
+     b. Let baseObj be ? ToObject(ref.[[Base]]).
+---*/
+
+var base = undefined;
+
+assert.throws(TypeError, function() {
+  delete base[0];
+});

test/language/expressions/delete/member-identifier-reference-null.js

@@ -0,0 +1,21 @@
+// Copyright (C) 2021 the V8 project authors. All rights reserved.
+// This code is governed by the BSD license found in the LICENSE file.
+
+/*---
+esid: sec-delete-operator
+description: Delete Operator throws an error if the base reference is not object-coercible (null).
+info: |
+  # 12.5.3.2 Runtime Semantics: Evaluation
+  UnaryExpression : delete UnaryExpression
+
+  [...]
+  5. If IsPropertyReference(ref) is true, then
+     a. If IsSuperReference(ref) is true, throw a ReferenceError exception.
+     b. Let baseObj be ? ToObject(ref.[[Base]]).
+---*/
+
+var base = null;
+
+assert.throws(TypeError, function() {
+  delete base.prop;
+});