Add llc -O0 line that triggers instruction selection failure

Author: jmmartinez

llvm/test/CodeGen/AMDGPU/extract_vector_dynelt.ll

@@ -1,5 +1,7 @@
 ; NOTE: Assertions have been autogenerated by utils/update_llc_test_checks.py UTC_ARGS: --version 5
 ; RUN: llc -mtriple=amdgcn -mcpu=fiji < %s | FileCheck -check-prefixes=GCN %s
+; RUN: not --crash llc -O0 -mtriple=amdgcn -mcpu=fiji < %s -o /dev/null 2>&1 | FileCheck --check-prefixes=GCN-O0 %s
+; GCN-O0: LLVM ERROR: Cannot select: t{{[0-9]+}}: i32 = extract_vector_elt
 
 define amdgpu_kernel void @float4_extelt(ptr addrspace(1) %out, i32 %sel) {
 ; GCN-LABEL: float4_extelt:

llvm/test/CodeGen/AMDGPU/insert_vector_dynelt.ll

@@ -1,5 +1,7 @@
 ; NOTE: Assertions have been autogenerated by utils/update_llc_test_checks.py
 ; RUN: llc -mtriple=amdgcn -mcpu=fiji < %s | FileCheck -enable-var-scope -check-prefixes=GCN %s
+; RUN: not --crash llc -O0 -mtriple=amdgcn -mcpu=fiji < %s -o /dev/null 2>&1 | FileCheck --check-prefixes=GCN-O0 %s
+; GCN-O0: LLVM ERROR: Cannot select: t{{[0-9]+}}: {{.*}} = insert_vector_elt
 
 define amdgpu_kernel void @float4_inselt(ptr addrspace(1) %out, <4 x float> %vec, i32 %sel) {
 ; GCN-LABEL: float4_inselt: