Port 07b03b83

Original Commit Message:

    c_entry_fp is normally cleared in `LeaveExitFrame`, but we adjust
    the frame without it in the exception path.

    This can cause the SafeStackFrameIterator to assume we have an exit
    frame and iterate over frames incorrectly, which for arm64 can
    cause pointer authentication failures with CFI enabled. Even without
    the pointer authentication failure, we iterate over frames
incorrectly,
    so make this change for other architectures too.

    Also clear c_entry_fp in the beginning of JSEntry, after pushing it
    on the stack. Not doing this doesn't cause pointer authentication
    failures, but it will make the SafeStackFrameIterator assume we
    are executing C++ and miss the JS frames on top.

R=georgia.kouveli@arm.com, joransiu@ca.ibm.com, junyan@redhat.com,
midawson@redhat.com, mfarazma@redhat.com
BUG=
LOG=N

Change-Id: Id12286a0f18fce928f9e44825fc13cd0338bac46
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/2665893Reviewed-by: Milad Fa <mfarazma@redhat.com>
Commit-Queue: Junliang Yan <junyan@redhat.com>
Cr-Commit-Position: refs/heads/master@{#72466}