Added coverage check for extensionless headers, and exclude hidden dot directoryies.

llvm-svn: 254785
diff --git a/clang-tools-extra/modularize/ModularizeUtilities.cpp b/clang-tools-extra/modularize/ModularizeUtilities.cpp
index 08c92fc..1db6018 100644
--- a/clang-tools-extra/modularize/ModularizeUtilities.cpp
+++ b/clang-tools-extra/modularize/ModularizeUtilities.cpp
@@ -468,7 +468,7 @@
 bool ModularizeUtilities::isHeader(StringRef FileName) {
   StringRef Extension = llvm::sys::path::extension(FileName);
   if (Extension.size() == 0)
-    return false;
+    return true;
   if (Extension.equals_lower(".h"))
     return true;
   if (Extension.equals_lower(".inc"))