Fixed modularize to warn about missing headers referenced in a module map.

llvm-svn: 239122
diff --git a/clang-tools-extra/modularize/Modularize.cpp b/clang-tools-extra/modularize/Modularize.cpp
index 65ed3ea..667cd01 100644
--- a/clang-tools-extra/modularize/Modularize.cpp
+++ b/clang-tools-extra/modularize/Modularize.cpp
@@ -738,8 +738,8 @@
       ListFileNames, HeaderPrefix));
 
   // Get header file names and dependencies.
-  ModUtil->loadAllHeaderListsAndDependencies();
-
+  if (ModUtil->loadAllHeaderListsAndDependencies())
+    HadErrors = 1;
 
   // If we are in assistant mode, output the module map and quit.
   if (ModuleMapPath.length() != 0) {