Including specialization, e.g.:

  // Declare parameterized generic
  macro GenericMacroTest<T: type>(param: T): Object {
    return Undefined;
  }

  // Declare specialization of generic
  GenericMacroTest<Object>(param: Object): Object {
    return param;
  }

  ...
  assert(GenericMacroTest<Smi>(0) == Undefined);
  assert(GenericMacroTest<Smi>(1) == Undefined);
  assert(GenericMacroTest<Object>(Null) == Null);
  assert(GenericMacroTest<Object>(False) == False);
  ...

Known issue: specialization doesn't rigorously checked to verify
that specialization signature precisely matches generic declaration.

Change-Id: I9d9d96da4c5c8c9a76550844680e9e133a5edaed
Reviewed-on: https://chromium-review.googlesource.com/1043986
Commit-Queue: Daniel Clifford <danno@chromium.org>
Reviewed-by: Tobias Tebbi <tebbi@chromium.org>
Cr-Commit-Position: refs/heads/master@{#53203}