We can determine the signal stack, so use that information to
make better decisions about when to calculate the frame size
and when not to. This fixes a several tests where the memory
layout had the signal stack and main stack in position that
confused some of the greater-than/less-than comparisons.

Also cleanup certain types to avoid more casting than necessary.

PiperOrigin-RevId: 580221819
Change-Id: I0365b03e7893741603dc66e6d36a069d0b7f5404