PR target/82002 Part 2: Correct non-immediate offset/invalid INSN

PR target/82002 Part 2: Correct non-immediate offset/invalid INSN

When we are realigning the stack pointer, making an ms_abi to sysv_abi
call and allocating 2GiB or more on the stack we end up with an invalid
INSN due to a non-immediate offset.  This occurs both with and without
-mcall-ms2sysv-xlogues.  Additionally, the stack allocation with
-mcall-ms2sysv-xlogues is ignoring (silently disabling) stack checking,
stack clash checking and probing.

This patch fixes these problems by:

1. No longer allocate stack space in ix86_emit_outlined_ms2sysv_save.
2. Rearrange where we emit SSE saves or stub call:
   a. Before frame allocation when offset from frame to save area is >= 2GiB.
   b. After frame allocation when frame is < 2GiB.  (Stack allocations
      prior to the stub call can't be combined with those afterwards, so
      this is better when possible.)
3. Modify choose_baseaddr to take an optional scratch_regno argument
   and never return rtx that cannot be used as an immediate.

gcc:
	config/i386/i386.c (choose_basereg): Use optional scratch
	register and add assertion.
	(x86_emit_outlined_ms2sysv_save): Use scratch register when
	needed, and don't allocate stack.
	(ix86_expand_prologue): Rearrange where SSE saves/stub call is
	emitted, correct wrong allocation with -mcall-ms2sysv-xlogues.
	(ix86_emit_outlined_ms2sysv_restore): Fix non-immediate offsets.

gcc/testsuite:
	gcc.target/i386/pr82002-2a.c: Change from xfail to fail.
	gcc.target/i386/pr82002-2b.c: Likewise.

From-SVN: r254412