[PowerPC][NFC] Pre-commit test case for checking whether mtvsrbmi power10 instruction not used (#143956)

Verify whether the generated assembly for the following function
includes the mtvsrbmi instruction.
 vector unsigned char v00FF()
{
 vector unsigned char x = { 0xFF, 0,0,0, 0,0,0,0, 0,0,0,0, 0,0,0,0 };
 return x;
 }

Author: diggerlin

llvm/test/CodeGen/PowerPC/mtvsrbmi.ll

@@ -0,0 +1,44 @@
+; NOTE: Assertions have been autogenerated by utils/update_llc_test_checks.py UTC_ARGS: --version 5
+; Verify whether the generated assembly for the following function includes the mtvsrbmi instruction.
+; vector unsigned char v00FF()
+; {
+; vector unsigned char x = { 0xFF, 0,0,0, 0,0,0,0, 0,0,0,0, 0,0,0,0 };
+; return x;
+; }
+
+; RUN: llc < %s -ppc-asm-full-reg-names  -mtriple=powerpc-ibm-aix -mcpu=pwr10  -verify-machineinstrs \
+; RUN:   | FileCheck %s --check-prefix=CHECK
+
+define dso_local noundef range(i8 -1, 1) <16 x i8> @_Z5v00FFv() {
+; CHECK-LABEL: _Z5v00FFv:
+; CHECK:       # %bb.0: # %entry
+; CHECK-NEXT:    lwz r3, L..C0(r2) # %const.0
+; CHECK-NEXT:    lxv vs34, 0(r3)
+; CHECK-NEXT:    blr
+entry:
+  ret <16 x i8> <i8 -1, i8 0, i8 0, i8 0, i8 0, i8 0, i8 0, i8 0, i8 0, i8 0, i8 0, i8 0, i8 0, i8 0, i8 0, i8 0>
+}
+
+; CHECK:      L..CPI0_0:
+; CHECK-NEXT:   .byte   255                             # 0xff
+; CHECK-NEXT:   .byte   0                               # 0x0
+; CHECK-NEXT:   .byte   0                               # 0x0
+; CHECK-NEXT:   .byte   0                               # 0x0
+; CHECK-NEXT:   .byte   0                               # 0x0
+; CHECK-NEXT:   .byte   0                               # 0x0
+; CHECK-NEXT:   .byte   0                               # 0x0
+; CHECK-NEXT:   .byte   0                               # 0x0
+; CHECK-NEXT:   .byte   0                               # 0x0
+; CHECK-NEXT:   .byte   0                               # 0x0
+; CHECK-NEXT:   .byte   0                               # 0x0
+; CHECK-NEXT:   .byte   0                               # 0x0
+; CHECK-NEXT:   .byte   0                               # 0x0
+; CHECK-NEXT:   .byte   0                               # 0x0
+; CHECK-NEXT:   .byte   0                               # 0x0
+; CHECK-NEXT:   .byte   0                               # 0x0
+
+; CHECK:      ._Z5v00FFv:
+; CHECK-NEXT: # %bb.0:
+; CHECK-NEXT:   lwz r3, L..C0(r2)
+; CHECK-NEXT:   lxv vs34, 0(r3)
+; CHECK-NEXT:   blr