[codeview] Fix YAML for LF_TYPESERVER2 by hoisting PDB_UniqueId

Summary:
We were treating the GUIDs in TypeServer2Record as strings, and the
non-ASCII bytes in the GUID would not round-trip through YAML.

We already had the PDB_UniqueId type portably represent a Windows GUID,
but we need to hoist that up to the DebugInfo/CodeView library so that
we can use it in the TypeServer2Record as well as in PDB parsing code.

Reviewers: inglorion, amccarth

Subscribers: llvm-commits, hiraditya

Differential Revision: https://reviews.llvm.org/D35495

llvm-svn: 308234
diff --git a/llvm/lib/DebugInfo/PDB/Native/NativeExeSymbol.cpp b/llvm/lib/DebugInfo/PDB/Native/NativeExeSymbol.cpp
index cb0830f..3241000 100644
--- a/llvm/lib/DebugInfo/PDB/Native/NativeExeSymbol.cpp
+++ b/llvm/lib/DebugInfo/PDB/Native/NativeExeSymbol.cpp
@@ -56,12 +56,12 @@
   return File.getFilePath();
 }
 
-PDB_UniqueId NativeExeSymbol::getGuid() const {
+codeview::GUID NativeExeSymbol::getGuid() const {
   auto IS = File.getPDBInfoStream();
   if (IS)
     return IS->getGuid();
   consumeError(IS.takeError());
-  return PDB_UniqueId{{0}};
+  return codeview::GUID{{0}};
 }
 
 bool NativeExeSymbol::hasCTypes() const {