Revert "Revert "DI: LLVM schema change: fold constants into string""

This reverts commit r218917, effectively reapplying r218913.  Original
commit message follows.

--

Update debug info testcases for an LLVM metadata schema change to fold
metadata constant operands into a single `MDString`.

Part of PR17891.

llvm-svn: 219011
diff --git a/clang/test/CodeGenCXX/debug-info-decl-nested.cpp b/clang/test/CodeGenCXX/debug-info-decl-nested.cpp
index bb0b5cf..3b36ce5 100644
--- a/clang/test/CodeGenCXX/debug-info-decl-nested.cpp
+++ b/clang/test/CodeGenCXX/debug-info-decl-nested.cpp
@@ -21,13 +21,14 @@
   OuterClass(const Foo *); // line 10
 };
 OuterClass::InnerClass OuterClass::theInnerClass; // This toplevel decl causes InnerClass to be generated.
-// CHECK0: metadata {{.*}}, metadata ![[DECL]], metadata {{.*}}, i32 [[@LINE+1]]} ; [ DW_TAG_subprogram ] [line [[@LINE+1]]] [def] [OuterClass]
+// CHECK0: metadata !"0x2e\00OuterClass\00{{.*}}\00[[@LINE+1]]"{{.*}}, metadata ![[DECL]], metadata {{![0-9]+}}} ; [ DW_TAG_subprogram ] [line [[@LINE+1]]] [def] [OuterClass]
 OuterClass::OuterClass(const Foo *meta) { } // line 13
 
 
 
 
 
+
 class Foo1;
 class OuterClass1
 {
@@ -36,7 +37,7 @@
     InnerClass1();
   } theInnerClass1;
 // CHECK1: [[DECL:[0-9]+]] = {{.*}} ; [ DW_TAG_subprogram ] [line [[@LINE+2]]] [Bar]
-// CHECK1: metadata {{.*}}, metadata ![[DECL]], metadata {{.*}}, i32 [[@LINE+4]]} ; [ DW_TAG_subprogram ] [line [[@LINE+4]]] [def] [Bar]
+// CHECK1: metadata !"0x2e\00Bar\00{{.*}}\00[[@LINE+4]]"{{.*}}, metadata ![[DECL]], metadata {{![0-9]+}}} ; [ DW_TAG_subprogram ] [line [[@LINE+4]]] [def] [Bar]
   void Bar(const Foo1 *);
 };
 OuterClass1::InnerClass1 OuterClass1::theInnerClass1;
@@ -57,5 +58,5 @@
   ~OuterClass2(); // line 10
 };
 OuterClass2::InnerClass2 OuterClass2::theInnerClass2;
-// CHECK2: metadata {{.*}}, metadata ![[DECL]], metadata {{.*}}, i32 [[@LINE+1]]} ; [ DW_TAG_subprogram ] [line [[@LINE+1]]] [def] [~OuterClass2]
+// CHECK2: metadata !"0x2e\00~OuterClass2\00{{.*}}\00[[@LINE+1]]"{{.*}}, metadata ![[DECL]], metadata {{.*}}} ; [ DW_TAG_subprogram ] [line [[@LINE+1]]] [def] [~OuterClass2]
 OuterClass2::~OuterClass2() { }