llvm-cov: Push some more debug output into the View (NFC)

llvm-svn: 217984
diff --git a/llvm/tools/llvm-cov/SourceCoverageView.cpp b/llvm/tools/llvm-cov/SourceCoverageView.cpp
index 2a212e5..2ad3e14 100644
--- a/llvm/tools/llvm-cov/SourceCoverageView.cpp
+++ b/llvm/tools/llvm-cov/SourceCoverageView.cpp
@@ -235,6 +235,10 @@
         OS << "\n";
       }
       // Render the child subview
+      if (Options.Debug)
+        errs() << "Expansion at line " << NextESV->getLine() << ", "
+               << NextESV->getStartCol() << " -> " << NextESV->getEndCol()
+               << "\n";
       NextESV->View->render(OS, false, NestedIndent);
       RenderedSubView = true;
     }