MIPS64: madd_d loses precision on loongson 3A chip.

On Loongson 3A chip, madd_d is different from mips64, this will cause failure
test/benchmarks/sunspider/3d-cube. Synthesize madd from mul and add.

TEST: benchmarks/sunspider/3d-cube
      benchmarks/sunspider/3d-raytrace
      benchmarks/sunspider/access-nbody
MIPS64: Init TickSample.state on mips64 HW.

TEST: cctest/**/*WithProfiler
MIPS64: Restore default value of FLAG_code_comments.