[llvm-pdbdump] Many minor fixes and improvements

A short list of some of the improvements:

1) Now supports -all command line argument, which implies many
   other command line arguments to simplify usage.
2) Now supports -no-compiler-generated command line argument to
   exclude compiler generated types.
3) Prints base class list.
4) -class-definitions implies -types.
5) Proper display of bitfields.
6) Can now distinguish between struct/class/interface/union.

And a few other minor tweaks.

llvm-svn: 230933
diff --git a/llvm/tools/llvm-pdbdump/BuiltinDumper.cpp b/llvm/tools/llvm-pdbdump/BuiltinDumper.cpp
index 1c1fe89..d808298 100644
--- a/llvm/tools/llvm-pdbdump/BuiltinDumper.cpp
+++ b/llvm/tools/llvm-pdbdump/BuiltinDumper.cpp
@@ -81,7 +81,7 @@
     WithColor(Printer, PDB_ColorItem::Type).get() << "HRESULT";
     break;
   default:
-    WithColor(Printer, PDB_ColorItem::Type).get() << "(unknown)";
+    WithColor(Printer, PDB_ColorItem::Type).get() << "void";
     break;
   }
 }