[Matrix] Add test for running matrix lowering with -O0.

llvm/test/Other/opt-O0-pipeline-enable-matrix.ll

@@ -0,0 +1,24 @@
+; RUN: opt -O0 -enable-matrix -debug-pass=Structure < %s -o /dev/null 2>&1 | FileCheck %s
+
+; REQUIRES: asserts
+
+; CHECK:      Pass Arguments:
+; CHECK-NEXT: Target Transform Information
+; CHECK-NEXT: Target Library Information
+; CHECK-NEXT: Assumption Cache Tracker
+; CHECK-NEXT:   FunctionPass Manager
+; CHECK-NEXT:     Module Verifier
+; CHECK-NEXT:     Instrument function entry/exit with calls to e.g. mcount() (pre inlining)
+; CHECK-NEXT:     Dominator Tree Construction
+; CHECK-NEXT:     Natural Loop Information
+; CHECK-NEXT:     Lazy Branch Probability Analysis
+; CHECK-NEXT:     Lazy Block Frequency Analysis
+; CHECK-NEXT:     Optimization Remark Emitter
+; CHECK-NEXT:     Basic Alias Analysis (stateless AA impl)
+; CHECK-NEXT:     Function Alias Analysis Results
+; CHECK-NEXT:     Lower the matrix intrinsics
+
+
+define void @f() {
+  ret void
+}