[CodeGen][test] Use FileCheck variable matchers for better test support

Summary: Depending on how clang is built, it may discard the IR names and use names like `%2` instead of `%result.ptr`, causing tests that rely on the IR name to fail. Using FileCheck matchers makes the test work regardless of how clang is built.

This test passes with both `-fno-discard-value-names` and `-fdiscard-value-names` to make sure it passes regardless of the build mode.

Reviewers: rnk, akhuang, aprantl, lebedev.ri

Subscribers: cfe-commits

Tags: #clang

Differential Revision: https://reviews.llvm.org/D63625

llvm-svn: 363996

clang/test/CodeGenCXX/debug-info-nrvo.cpp

@@ -1,5 +1,10 @@
-// RUN: %clangxx -target x86_64-unknown-unknown -g %s -emit-llvm -S -o - | FileCheck %s
-// RUN: %clangxx -target x86_64-unknown-unknown -g -fno-elide-constructors %s -emit-llvm -S -o - | FileCheck %s -check-prefix=NOELIDE
+// RUN: %clangxx -target x86_64-unknown-unknown -g \
+// RUN:   %s -emit-llvm -S -o - | FileCheck %s
+
+// RUN: %clangxx -target x86_64-unknown-unknown -g \
+// RUN:   -fno-elide-constructors %s -emit-llvm -S -o - | \
+// RUN:   FileCheck %s -check-prefix=NOELIDE
+
 struct Foo {
   Foo() = default;
   Foo(Foo &&other) { x = other.x; }
@@ -21,8 +26,10 @@ int main() {
 // Check that NRVO variables are stored as a pointer with deref if they are
 // stored in the return register.
 
-// CHECK: %result.ptr = alloca i8*, align 8
-// CHECK: call void @llvm.dbg.declare(metadata i8** %result.ptr,
+// CHECK: %[[RESULT:.*]] = alloca i8*, align 8
+// CHECK: call void @llvm.dbg.declare(metadata i8** %[[RESULT]],
 // CHECK-SAME: metadata !DIExpression(DW_OP_deref)
-// NOELIDE: call void @llvm.dbg.declare(metadata %struct.Foo* %foo,
+
+// NOELIDE: %[[FOO:.*]] = alloca %struct.Foo, align 4
+// NOELIDE: call void @llvm.dbg.declare(metadata %struct.Foo* %[[FOO]],
 // NOELIDE-SAME:                        metadata !DIExpression()