Fix ClassMirror.typeArguments handling for dynamic only type arguments

Fix ClassMirror.typeArguments handling for dynamic only type arguments.

Addresses an issue where we did not return the appropriate type arguments for instances with all dynamic type arguments.

Example:
Class <E> {}

main() {
  var cm = reflectClass(new C()).type;
  print(cm.typeArguments);  
  // now prints: {Symbol("E"): TypeMirror on 'dynamic'}
  // previously: crashed
}

BUG=
R=asiva@google.com

Committed: https://code.google.com/p/dart/source/detail?r=26135

[rmacnak, 2013-08-14 00:07:41]

https://codereview.chromium.org/23133003/diff/1/runtime/lib/mirrors.cc
File runtime/lib/mirrors.cc (right):

https://codereview.chromium.org/23133003/diff/1/runtime/lib/mirrors.cc#newcod...
runtime/lib/mirrors.cc:598: if (num_params == 0) return
Object::empty_array().raw();
While I think this looks better, we use braces even for one-line conditionals.

[Michael Lippautz (Google), 2013-08-14 00:14:08]

https://codereview.chromium.org/23133003/diff/1/runtime/lib/mirrors.cc
File runtime/lib/mirrors.cc (right):

https://codereview.chromium.org/23133003/diff/1/runtime/lib/mirrors.cc#newcod...
runtime/lib/mirrors.cc:598: if (num_params == 0) return
Object::empty_array().raw();
On 2013/08/14 00:07:41, Ryan Macnak wrote:
> While I think this looks better, we use braces even for one-line conditionals.

Done.

[siva, 2013-08-14 00:22:09]

https://codereview.chromium.org/23133003/diff/1/runtime/lib/mirrors.cc
File runtime/lib/mirrors.cc (right):

https://codereview.chromium.org/23133003/diff/1/runtime/lib/mirrors.cc#newcod...
runtime/lib/mirrors.cc:607: // arguments have been provided, or all arguments
have been dynamic. Return a
or all arguments are dynamic

https://codereview.chromium.org/23133003/diff/1/runtime/lib/mirrors.cc#newcod...
runtime/lib/mirrors.cc:617: 
ASSERT(args.Length() >= num_params);

[Michael Lippautz (Google), 2013-08-14 16:29:29]

https://codereview.chromium.org/23133003/diff/1/runtime/lib/mirrors.cc
File runtime/lib/mirrors.cc (right):

https://codereview.chromium.org/23133003/diff/1/runtime/lib/mirrors.cc#newcod...
runtime/lib/mirrors.cc:607: // arguments have been provided, or all arguments
have been dynamic. Return a
On 2013/08/14 00:22:09, siva wrote:
> or all arguments are dynamic

Done.

https://codereview.chromium.org/23133003/diff/1/runtime/lib/mirrors.cc#newcod...
runtime/lib/mirrors.cc:617: 
On 2013/08/14 00:22:09, siva wrote:
> ASSERT(args.Length() >= num_params);

Done.

[siva, 2013-08-14 18:30:53]

lgtm

[Michael Lippautz (Google), 2013-08-14 18:41:34]

Committed patchset #3 manually as r26135 (presubmit successful).