Remove the last remnants of the TranscendentalCache.

It was only used for Math.log, and even then only in full code and in %_MathLog. For crankshafted code, Intel already used the FP operations directly, while the ARM/MIPS ports were a bit lazy and simply called the stub. The latter directly call the C library now without any cache. It would be possible to directly generate machine code if somebody has the time, from what I've seen out in the wild it should be only about a dozen instructions.

LOG=y
R=yangguo@chromium.org

Review URL: https://codereview.chromium.org/113343003

git-svn-id: https://v8.googlecode.com/svn/branches/bleeding_edge@18344 ce2b1a6d-e550-0410-aec6-3dcde31c8c00