The x64 and ia32 implementations are the same, modulo function
signature. x64 has a kScratchDoubleReg available, ia32 takes it as a
argument. We standardize on the ia32 function signature and have callers
on x64 pass in the scratch register.

Bug: v8:11589
Change-Id: I2f75705ed9c618d6e7a7e34ac96b78b772c4944d
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/2786094Reviewed-by: Bill Budge <bbudge@chromium.org>
Commit-Queue: Zhi An Ng <zhin@chromium.org>
Cr-Commit-Position: refs/heads/master@{#73676}