Add -verify-machineinstrs to RUN line

Author: mbrkusanin

llvm/test/CodeGen/AMDGPU/vgpr-mark-last-scratch-load.mir

@@ -1,5 +1,5 @@
 # NOTE: Assertions have been autogenerated by utils/update_mir_test_checks.py UTC_ARGS: --version 3
-# RUN: llc -mtriple=amdgcn-amd-amdhsa -mcpu=gfx1200 -o - %s -run-pass=greedy -run-pass=amdgpu-mark-last-scratch-load | FileCheck -check-prefix=CHECK %s
+# RUN: llc -mtriple=amdgcn-amd-amdhsa -mcpu=gfx1200 -o - %s -run-pass=greedy -run-pass=amdgpu-mark-last-scratch-load -verify-machineinstrs | FileCheck -check-prefix=CHECK %s
 
 --- |
   define amdgpu_cs void @test_spill_12x32() "amdgpu-num-vgpr"="12" {