i386: Fix -fcf-protection -Os ICE due to movabsq peephole2 [PR112845]

i386: Fix -fcf-protection -Os ICE due to movabsq peephole2 [PR112845]

The following testcase ICEs in the movabsq $(i32 << shift), r64 peephole2
I've added a while back to use smaller code than movabsq if possible.
If i32 is 0xfa1e0ff3 and shift is not divisible by 8, then it creates
an invalid insn (as 0xfa1e0ff3 CONST_INT is not allowed as
x86_64_immediate_operand nor x86_64_zext_immediate_operand), the peephole2
even triggers on it again and again (this time with shift 0) until it gives
up.

The following patch fixes that.  As ix86_endbr_immediate_operand needs a
CONST_INT and it is hopefully rare, I chose to use FAIL rather than handling
it in the condition (where I'd probably need to call ctz_hwi again etc.).

2023-12-05  Jakub Jelinek  <jakub@redhat.com>

	PR target/112845
	* config/i386/i386.md (movabsq $(i32 << shift), r64 peephole2): FAIL
	if the new immediate is ix86_endbr_immediate_operand.