Implement ParameterMirror.metadata.

Implement ParameterMirror.metadata.

BUG=http://dartbug.com/10906
BUG=http://dartbug.com/11418
R=asiva@google.com

Committed: https://code.google.com/p/dart/source/detail?r=27082

[rmacnak, 2013-08-23 22:08:16]

Waiting on https://codereview.chromium.org/23020025/

[siva, 2013-08-26 05:11:45]

The metadata stuff looks fine but could you upload this CL once 
https://codereview.chromium.org/23020025/ is committed so that it is easy to see
new code.

[rmacnak, 2013-08-27 21:02:12]

Reuploaded based on Michael's commit.

[siva, 2013-08-28 23:26:47]

LGTM once named constant is used instead of '3'.

https://codereview.chromium.org/23224016/diff/10001/runtime/lib/mirrors.cc
File runtime/lib/mirrors.cc (right):

https://codereview.chromium.org/23224016/diff/10001/runtime/lib/mirrors.cc#ne...
runtime/lib/mirrors.cc:158: ASSERT(param_descriptor.Length() == (3 *
non_implicit_param_count));
You should probably make 3 a named constant,
const intptr_t kNumEntriesPerParam = 3; or something like that.

(maybe this constant should be in parser.h).

https://codereview.chromium.org/23224016/diff/10001/runtime/vm/parser.cc
File runtime/vm/parser.cc (right):

https://codereview.chromium.org/23224016/diff/10001/runtime/vm/parser.cc#newc...
runtime/vm/parser.cc:802: param_descriptor.SetAt(j, param[i].is_final ?
Bool::True() :
Ditto comment about '3' here.

https://codereview.chromium.org/23224016/diff/10001/runtime/vm/parser.h
File runtime/vm/parser.h (right):

https://codereview.chromium.org/23224016/diff/10001/runtime/vm/parser.h#newco...
runtime/vm/parser.h:151: // contains a bool indicating whether the parameter has
been final, (3*i+1)
Ditto comment about '3' here.

[rmacnak, 2013-08-29 01:25:47]

Gave the parameter entry size and offsets named constants using the same pattern
as, eg, ArgumentsDescriptor.

[siva, 2013-09-03 21:32:46]

lgtm

[rmacnak, 2013-09-03 22:50:20]

Committed patchset #6 manually as r27082 (presubmit successful).