Fix allocatable regs to prevent conflicts with r11/r12.

r11 is currently the lithium scratch reg
r12 is currently ip
FullCodeGenerator::EmitProfilingCounterReset must be fixed length.

... due to Deoptimizer::PatchStackCheckCodeAt's dependency.
Implement LCodeGen::DoMathFloor
Introduce 64bit specific instructions, now able to execute a few instructions in 64bit mode.
Merge branch 'master' of github.com:andrewlow/v8ppc
Fix simulator build-break.
Implement LCodeGen::DoDeferredNumberTagI

Also, simplify FloatingPointHelper::ConvertIntToDouble and
FloatingPointHelper::ConvertUnsignedIntToDouble to use fcfid.
Implement LCodeGen::DoMathRound
Implement LCodeGen::DoMathPowHalf
Pass floating point arguments in registers.
Remove ARM flags from simulator, enable 64bit registers in simulator.
Merge branch 'master' of github.com:andrewlow/v8ppc
Logical shift right by zero must produce a positive result.
Code cleanup: use helpers for integer -> double conversion
Address issue #78, check correct condition register in StringCompareStub::GenerateCompareFlatAsciiStrings
Add capability to simulate on native. (make nativesim=true)
Add "info" simulator feature, which allows for printing a string and
continuing (similar conditional stop).
Adding '__ info("your message");' within code causes the simulator to
print that message when its associated breakpoint is hit. One useful way
to use it is to add it to the define of the EMIT_STUB_MARKER macro:
EMIT_STUB_MARKER(stub_marker) __ info(__FUNCTION__) __ marker_asm(stub_marker).
Detect neg instruction overflow.
Fix for 64-bit build break due to info() changes.
more 64bit simulation support
fix presubmit error