Ensure consistent result of transcendental functions.

Ensure consistent result of transcendental functions.

BUG=
TEST=regress-transcendental.js

Committed: https://code.google.com/p/v8/source/detail?r=10908

[Yang, 2012-03-02 13:24:32]

This CL:
- actually enables inlining of Math.tan in crankshaft
- makes sure that we always use the FPU to calculate sin, cos, tan and log on
ia32 and x64, in both runtime call and generated code

PTAL.

[Sven Panne, 2012-03-02 14:01:21]

LGTM. Just a remark: We could generate all fast_foo stubs in
V8::InitializeOncePerProcess(), removing the need for a separate mutex. We could
even generate all those stubs (incl. the modulo stub) in a single tiny region.
But OTOH programs might not need those stubs at all. It's a judgement call...