Add DWARF discriminator support to DILexicalBlocks.

This adds support for emitting discriminators from DILexicalBlocks.

llvm-svn: 202736
diff --git a/llvm/lib/IR/DebugInfo.cpp b/llvm/lib/IR/DebugInfo.cpp
index 506f2dd..749e0b5 100644
--- a/llvm/lib/IR/DebugInfo.cpp
+++ b/llvm/lib/IR/DebugInfo.cpp
@@ -600,7 +600,7 @@
 
 /// \brief Verify that the lexical block descriptor is well formed.
 bool DILexicalBlock::Verify() const {
-  return isLexicalBlock() && DbgNode->getNumOperands() == 6;
+  return isLexicalBlock() && DbgNode->getNumOperands() == 7;
 }
 
 /// \brief Verify that the file-scoped lexical block descriptor is well formed.