The LinkageLocation currently consists of two fields, a bit_field and a
machine_type. The existing equality check only checked the equality of
the bit_field, which meant that a FP register location and a GP register
location could alias. I added a static {IsSameLocation} function which
checks that not just the bit_field but also if one of the two locations
at least has a subtype of the other. Note that we do not check for
type-equality because {CanTailCall} checks, which are the main user of
the LinkageLocation equality check, should pass even if the result types
are in a sub-typing relationship.

R=mstarzinger@chromium.org

Bug: v8:9396
Change-Id: Iaa2d11311d0c18e8ffc1dd934e369106ab2456a6
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/1763533
Commit-Queue: Andreas Haas <ahaas@chromium.org>
Reviewed-by: Michael Starzinger <mstarzinger@chromium.org>
Cr-Commit-Position: refs/heads/master@{#63319}