Fixes ABI bug in MIPS.

Fixes ABI bug in MIPS.

Adds test for native extensions with autoscoping set to false.

R=asiva@google.com

Committed: https://code.google.com/p/dart/source/detail?r=32147

[siva, 2014-01-29 22:04:02]

LGTM,

Couple of comments:
- do we need a completely new sample extension test just for setting auto scope
to false, would it be sufficient to set one out of the 3 native methods in the
original sample extension test to have auto scope set to false
- Maybe long term we could change the stub code API to pass the native entry
point in T9 instead of T5

https://codereview.chromium.org/131103025/diff/1/runtime/vm/stub_code_mips.cc
File runtime/vm/stub_code_mips.cc (right):

https://codereview.chromium.org/131103025/diff/1/runtime/vm/stub_code_mips.cc...
runtime/vm/stub_code_mips.cc:1044: __ jalr(T9);  // S4 is the arguments
descriptor array.
Here we are calling Dart code, do we need to be defensive? Can we just add a
comment stating that we are calling Dart and hence there and no MIPS ABI
requirements?

[zra, 2014-01-29 22:49:57]

Thanks. I removed the new sample extension, and just added a method with
autoscope=false to the existing one. Re-verified crash and fix on the test.

https://codereview.chromium.org/131103025/diff/1/runtime/vm/stub_code_mips.cc
File runtime/vm/stub_code_mips.cc (right):

https://codereview.chromium.org/131103025/diff/1/runtime/vm/stub_code_mips.cc...
runtime/vm/stub_code_mips.cc:1044: __ jalr(T9);  // S4 is the arguments
descriptor array.
On 2014/01/29 22:04:03, siva wrote:
> Here we are calling Dart code, do we need to be defensive? Can we just add a
> comment stating that we are calling Dart and hence there and no MIPS ABI
> requirements?

Done.

[zra, 2014-01-29 23:07:56]

Committed patchset #3 manually as r32147 (presubmit successful).