MIPS: CodeStubs contain their corresponding Isolate* now. (part 2)

Port r20940 (a5dde97)

Original commit message:
This CL mechanically removes all useless Isolate* parameters from code
stub functions, making things quite a bit simpler.

BUG=359977
LOG=y
R=plind44@gmail.com

Review URL: https://codereview.chromium.org/251473004

Patch from Balazs Kilvady <kilvadyb@homejinni.com>.

git-svn-id: https://v8.googlecode.com/svn/branches/bleeding_edge@20945 ce2b1a6d-e550-0410-aec6-3dcde31c8c00