Add a negative test case

Author: luciechoi

llvm/test/CodeGen/SPIRV/extensions/SPV_KHR_maximal_reconvergence/enable-maximal-reconvergence.ll

@@ -1,12 +1,20 @@
-; RUN: llc -O0 -verify-machineinstrs -mtriple=spirv1.6-unknown-vulkan1.3-compute --spirv-ext=+SPV_KHR_maximal_reconvergence %s -o - | FileCheck %s
+; RUN: llc -O0 -verify-machineinstrs -mtriple=spirv1.6-unknown-vulkan1.3-compute --spirv-ext=+SPV_KHR_maximal_reconvergence %s -o - | FileCheck %s --check-prefix=CHECK-EXTENSION
 ; RUN: %if spirv-tools %{ llc -O0 -mtriple=spirv1.6-unknown-vulkan1.3-compute --spirv-ext=+SPV_KHR_maximal_reconvergence %s -o - -filetype=obj | spirv-val %}
 
-; CHECK: OpCapability Shader
-; CHECK: OpExtension "SPV_KHR_maximal_reconvergence"
-; CHECK: OpExecutionMode {{.*}} MaximallyReconvergesKHR
+; CHECK-EXTENSION: OpCapability Shader
+; CHECK-EXTENSION: OpExtension "SPV_KHR_maximal_reconvergence"
+; CHECK-EXTENSION: OpExecutionMode {{.*}} MaximallyReconvergesKHR
 define void @main() local_unnamed_addr #0 {
 entry:
   ret void
 }
 
-attributes #0 = { mustprogress nofree noinline norecurse nosync nounwind willreturn memory(none) "enable-maximal-reconvergence"="true" "frame-pointer"="all" "hlsl.numthreads"="1,1,1" "hlsl.shader"="compute" "no-infs-fp-math"="true" "no-nans-fp-math"="true" "no-signed-zeros-fp-math"="true" "no-trapping-math"="true" "stack-protector-buffer-size"="8" }
+; CHECK-EXTENSION-NOT: OpExtension "SPV_KHR_maximal_reconvergence"
+; CHECK-EXTENSION-NOT: OpExecutionMode {{.*}} MaximallyReconvergesKHR
+define void @negative() local_unnamed_addr #1 {
+entry:
+  ret void
+}
+
+attributes #0 = { "enable-maximal-reconvergence"="true" "hlsl.numthreads"="1,1,1" "hlsl.shader"="compute" }
+attributes #1 = { "hlsl.numthreads"="1,1,1" "hlsl.shader"="compute" }