MIPS: Make concrete classes for individual call descriptors. - external

MIPS: Make concrete classes for individual call descriptors. - external

Port r23639 (e5a2758)

Original commit message:
The ic-convention classes that hold register specifications are merged into these new call descriptor classes, which should represent a final home for that information.

BUG=

[balazs.kilvady, 2014-09-03 16:51:54]

balazs.kilvady@imgtec.com changed reviewers:
+ akos.palfi@imgtec.com, danno@chromium.org, dusan.milosavljevic@imgtec.com,
gergely.kis@imgtec.com, machenbach@chromium.org, paul.lind@imgtec.com

[balazs.kilvady, 2014-09-03 16:53:42]

We need a v8 team reviewer for this one. We will land this CL after the MIPS
specific part is reviewed and landed.

[balazs.kilvady, 2014-09-03 17:50:59]

balazs.kilvady@imgtec.com changed reviewers:
+ mvstanton@chromium.org

[Michael Achenbach, 2014-09-03 21:26:14]

lgtm

[akos.palfi.imgtec, 2014-09-03 22:27:04]

Committed as r23667.