[X86][test] Add test to check ah is not allocatable for register class gr8_norex2

This test should be added after llvm#73529

Author: KanRobert

llvm/test/CodeGen/X86/apx/gr8_norex2.ll

@@ -0,0 +1,9 @@
+; Check ah is not allocatable for register class gr8_norex2
+; RUN: not llc < %s -mtriple=x86_64-unknown-unknown 2>&1 | FileCheck %s
+
+define void @gr8_norex2() {
+; CHECK: error: inline assembly requires more registers than available
+  %1 = tail call i8 asm sideeffect "movb %r14b, $0", "=r,~{al},~{rbx},~{rcx},~{rdx},~{rdi},~{rsi},~{rbp},~{rsp},~{r8},~{r9},~{r10},~{r11},~{r12},~{r13},~{r14},~{r15},~{dirflag},~{fpsr},~{flags}"()
+  ret void
+}
+