http2,perf_hooks: perf state using AliasedBuffer

This is the portion of be2cbcc that is not in dea44b9.

Update performance_state to use AliasedBuffer and update usage sites.

Backport-PR-URL: #20456
PR-URL: #18300
Reviewed-By: Anna Henningsen <anna@addaleax.net>
Reviewed-By: James M Snell <jasnell@gmail.com>

src/node_http2.cc

@@ -531,7 +531,8 @@ Http2Session::~Http2Session() {
 }
 
 inline bool HasHttp2Observer(Environment* env) {
-  uint32_t* observers = env->performance_state()->observers;
+  AliasedBuffer<uint32_t, v8::Uint32Array>& observers =
+      env->performance_state()->observers;
   return observers[performance::NODE_PERFORMANCE_ENTRY_TYPE_HTTP2] != 0;
 }