Fix global_asm macro pretty printing

compiler/rustc_ast_pretty/src/pprust/state/item.rs

@@ -218,6 +218,8 @@ impl<'a> State<'a> {
             ast::ItemKind::GlobalAsm(ref asm) => {
                 self.head(visibility_qualified(&item.vis, "global_asm!"));
                 self.print_inline_asm(asm);
+                self.word(";");
+                self.end();
                 self.end();
             }
             ast::ItemKind::TyAlias(box ast::TyAlias {

src/test/ui/asm/unpretty-expanded.rs

@@ -0,0 +1,3 @@
+// check-pass
+// compile-flags: -Zunpretty=expanded
+core::arch::global_asm!("x: .byte 42");

src/test/ui/asm/unpretty-expanded.stdout

@@ -0,0 +1,9 @@
+#![feature(prelude_import)]
+#![no_std]
+#[prelude_import]
+use ::std::prelude::rust_2015::*;
+#[macro_use]
+extern crate std;
+// check-pass
+// compile-flags: -Zunpretty=expanded
+global_asm! ("x: .byte 42");