MIPS: The IC exposes a register definition.

Port r22011 (be22370)

Original commit message:
Centralize a register definition in an IC that provides:
1) symbolic names for the register (like, edx == receiver)
2) defines ordering when passed on the stack

Code that implements or uses the IC should use this definition instead of "knowing" what the registers are. Or at least have the definition to validate it's assumptions.

As a side effect of avoiding runtime static initializers (enforced by tools/check-static-initializers.sh, neat), I gave ownership of the registers array to CodeStubInterfaceDescriptor. This prompted a cleanup of that struct.

BUG=
R=mvstanton@chromium.org

Review URL: https://codereview.chromium.org/354863002

git-svn-id: https://v8.googlecode.com/svn/branches/bleeding_edge@22021 ce2b1a6d-e550-0410-aec6-3dcde31c8c00