Introduce class TypeRef in the VM to fully support recursive types.

Introduce class TypeRef in the VM to fully support recursive types.
Fix issues 15244, 15148, 14869, 14000, and 13688 (was closed, but fragile).

Note that the current solution is not final as it may not be correct in more
complex cases not yet covered by language tests.
The final solution will require a 'trail' instead of a simple mark bit to
prevent operations involving recursive types to diverge.

R=asiva@google.com

Committed: https://code.google.com/p/dart/source/detail?r=31087

[regis, 2013-12-11 02:48:04]

It's like Christmas: there is a bit for everyone. Feel free to review just the
parts you are familiar with.
We can discuss in person on Wednesday if you want some explanation before
starting the review.

Thanks,
Regis

[hausner, 2013-12-11 18:37:42]

No objections from me. Maybe a quick explanation in person would help to
understand how you find out when to create a TypeRef object.

[rmacnak, 2013-12-11 19:32:06]

Let's add asserts against TypeRefs becoming reflectees.

https://codereview.chromium.org/103913005/diff/1/runtime/lib/mirrors.cc
File runtime/lib/mirrors.cc (right):

https://codereview.chromium.org/103913005/diff/1/runtime/lib/mirrors.cc#newco...
runtime/lib/mirrors.cc:339: 
ASSERT(!type.IsTypeRef());

https://codereview.chromium.org/103913005/diff/1/runtime/lib/mirrors.cc#newco...
runtime/lib/mirrors.cc:385: if (type.HasResolvedTypeClass()) {
ASSERT(!type.IsTypeRef());

[siva, 2013-12-11 21:14:08]

lgtm

https://codereview.chromium.org/103913005/diff/1/runtime/vm/object.cc
File runtime/vm/object.cc (right):

https://codereview.chromium.org/103913005/diff/1/runtime/vm/object.cc#newcode...
runtime/vm/object.cc:3937: AbstractType& type = AbstractType::Handle();
AbstractType::Handle(isolate);
as you already have the isolate.

https://codereview.chromium.org/103913005/diff/1/runtime/vm/object.cc#newcode...
runtime/vm/object.cc:12431: return FinalizeHash(result);
indentation is off

[regis, 2013-12-11 22:47:46]

Thanks!

https://codereview.chromium.org/103913005/diff/1/runtime/lib/mirrors.cc
File runtime/lib/mirrors.cc (right):

https://codereview.chromium.org/103913005/diff/1/runtime/lib/mirrors.cc#newco...
runtime/lib/mirrors.cc:339: 
On 2013/12/11 19:32:07, Ryan Macnak wrote:
> ASSERT(!type.IsTypeRef());

Done.

https://codereview.chromium.org/103913005/diff/1/runtime/lib/mirrors.cc#newco...
runtime/lib/mirrors.cc:385: if (type.HasResolvedTypeClass()) {
On 2013/12/11 19:32:07, Ryan Macnak wrote:
> ASSERT(!type.IsTypeRef());

Done.

https://codereview.chromium.org/103913005/diff/1/runtime/vm/object.cc
File runtime/vm/object.cc (right):

https://codereview.chromium.org/103913005/diff/1/runtime/vm/object.cc#newcode...
runtime/vm/object.cc:3937: AbstractType& type = AbstractType::Handle();
On 2013/12/11 21:14:08, siva wrote:
> AbstractType::Handle(isolate);
> as you already have the isolate.

Done.

https://codereview.chromium.org/103913005/diff/1/runtime/vm/object.cc#newcode...
runtime/vm/object.cc:12431: return FinalizeHash(result);
On 2013/12/11 21:14:08, siva wrote:
> indentation is off

Done.

[regis, 2013-12-11 22:51:30]

Committed patchset #2 manually as r31087 (presubmit successful).