Rename some PDB classes.

We have a lot of very similarly named classes related to
dealing with module debug info.  This patch has NFC, it just
renames some classes to be more descriptive (albeit slightly
more to type).  The mapping from old to new class names is as
follows:

   Old          |        New
ModInfo         | DbiModuleDescriptor
ModuleSubstream | ModuleDebugFragment
ModStream       | ModuleDebugStream

With the corresponding Builder classes renamed accordingly.

Differential Revision: https://reviews.llvm.org/D32506

llvm-svn: 301555
diff --git a/llvm/lib/DebugInfo/PDB/Native/DbiStreamBuilder.cpp b/llvm/lib/DebugInfo/PDB/Native/DbiStreamBuilder.cpp
index a203aea..62bda65 100644
--- a/llvm/lib/DebugInfo/PDB/Native/DbiStreamBuilder.cpp
+++ b/llvm/lib/DebugInfo/PDB/Native/DbiStreamBuilder.cpp
@@ -12,8 +12,8 @@
 #include "llvm/ADT/ArrayRef.h"
 #include "llvm/DebugInfo/MSF/MSFBuilder.h"
 #include "llvm/DebugInfo/MSF/MappedBlockStream.h"
+#include "llvm/DebugInfo/PDB/Native/DbiModuleDescriptorBuilder.h"
 #include "llvm/DebugInfo/PDB/Native/DbiStream.h"
-#include "llvm/DebugInfo/PDB/Native/ModInfoBuilder.h"
 #include "llvm/DebugInfo/PDB/Native/RawError.h"
 #include "llvm/Object/COFF.h"
 #include "llvm/Support/BinaryStreamWriter.h"
@@ -74,10 +74,11 @@
          calculateSectionMapStreamSize() + calculateDbgStreamsSize();
 }
 
-Expected<ModInfoBuilder &>
+Expected<DbiModuleDescriptorBuilder &>
 DbiStreamBuilder::addModuleInfo(StringRef ModuleName) {
   uint32_t Index = ModiList.size();
-  auto MIB = llvm::make_unique<ModInfoBuilder>(ModuleName, Index, Msf);
+  auto MIB =
+      llvm::make_unique<DbiModuleDescriptorBuilder>(ModuleName, Index, Msf);
   auto M = MIB.get();
   auto Result = ModiMap.insert(std::make_pair(ModuleName, std::move(MIB)));