core: Behavior shouldn't be generic

We always pass around Box<[u8]>, and adding this generic is an
unnecessary complication.

Add deno_core_http_bench_test to test.py

sharedQueue works on deno_core_http_bench

core/shared_queue_test.js

@@ -0,0 +1,65 @@
+// Copyright 2018-2019 the Deno authors. All rights reserved. MIT license.
+
+function assert(cond) {
+  if (!cond) {
+    throw Error("assert");
+  }
+}
+
+function main() {
+  const q = Deno._sharedQueue;
+
+  let h = q.head();
+  assert(h > 0);
+
+  let r = new Uint8Array([1, 2, 3, 4, 5]);
+  let len = r.byteLength + h;
+  assert(q.push(r));
+  assert(q.head() == len);
+
+  r = new Uint8Array([6, 7]);
+  assert(q.push(r));
+
+  r = new Uint8Array([8, 9, 10, 11]);
+  assert(q.push(r));
+  assert(q.numRecords() == 3);
+  assert(q.size() == 3);
+
+  r = q.shift();
+  assert(r.byteLength == 5);
+  assert(r[0] == 1);
+  assert(r[1] == 2);
+  assert(r[2] == 3);
+  assert(r[3] == 4);
+  assert(r[4] == 5);
+  assert(q.numRecords() == 3);
+  assert(q.size() == 2);
+
+  r = q.shift();
+  assert(r.byteLength == 2);
+  assert(r[0] == 6);
+  assert(r[1] == 7);
+  assert(q.numRecords() == 3);
+  assert(q.size() == 1);
+
+  r = q.shift();
+  assert(r.byteLength == 4);
+  assert(r[0] == 8);
+  assert(r[1] == 9);
+  assert(r[2] == 10);
+  assert(r[3] == 11);
+  assert(q.numRecords() == 3);
+  assert(q.size() == 0);
+
+  assert(q.shift() == null);
+  assert(q.shift() == null);
+  assert(q.numRecords() == 3);
+  assert(q.size() == 0);
+
+  q.reset();
+  assert(q.numRecords() == 0);
+  assert(q.size() == 0);
+  libdeno.print("shared_queue_test.js ok\n");
+}
+
+main();