Add HeapNumber fast path to v8::Value::{Uint,Int}32Value()

Add HeapNumber fast path to v8::Value::{Uint,Int}32Value()

This has the added benefit that these functions are now guaranteed not to throw when v8::Value::Is{Uint,Int}32() returned true, even when calling into JavaScript would throw a stack limit error.

BUG=chromium:446097
LOG=y

Review URL: https://codereview.chromium.org/873983003

Cr-Commit-Position: refs/heads/master@{#26273}