i386: Fix up *avx2_eq<mode>3 constraints [PR114783]

i386: Fix up *avx2_eq<mode>3 constraints [PR114783]

The r14-4456 change (part of APX EGPR support) seems to have mistakenly
changed in the
@@ -16831,7 +16831,7 @@ (define_insn "*avx2_eq<mode>3"
   [(set (match_operand:VI_256 0 "register_operand" "=x")
        (eq:VI_256
          (match_operand:VI_256 1 "nonimmediate_operand" "%x")
-         (match_operand:VI_256 2 "nonimmediate_operand" "xm")))]
+         (match_operand:VI_256 2 "nonimmediate_operand" "jm")))]
   "TARGET_AVX2 && !(MEM_P (operands[1]) && MEM_P (operands[2]))"
   "vpcmpeq<ssemodesuffix>\t{%2, %1, %0|%0, %1, %2}"
   [(set_attr "type" "ssecmp")
hunk the xm constraint to jm, while in many other spots it changed correctly
xm to xjm.  The instruction doesn't require the last operand to be in
memory, it can handle 3 256-bit registers just fine, just it is a VEX only
encoded instruction and so can't allow APX EGPR regs in the memory operand.

The following patch fixes it, so that we don't force one of the == operands
into memory all the time.

2024-04-20  Jakub Jelinek  <jakub@redhat.com>

	PR target/114783
	* config/i386/sse.md (*avx2_eq<mode>3): Change last operand's
	constraint from "jm" to "xjm".

	* gcc.target/i386/avx2-pr114783.c: New test.