Add the beginning of PDB diffing support.

For now this only diffs the stream directory and the MSF
Superblock.  Future patches will drill down into individual
streams to find out where the differences lie.

Differential Revision: https://reviews.llvm.org/D30908

llvm-svn: 297689
diff --git a/llvm/tools/llvm-pdbdump/llvm-pdbdump.h b/llvm/tools/llvm-pdbdump/llvm-pdbdump.h
index d4f082c..cdebc20 100644
--- a/llvm/tools/llvm-pdbdump/llvm-pdbdump.h
+++ b/llvm/tools/llvm-pdbdump/llvm-pdbdump.h
@@ -67,6 +67,10 @@
 extern llvm::cl::opt<bool> DumpStringTable;
 }
 
+namespace diff {
+extern llvm::cl::opt<bool> Pedantic;
+}
+
 namespace pdb2yaml {
 extern llvm::cl::opt<bool> NoFileHeaders;
 extern llvm::cl::opt<bool> StreamMetadata;