Re-apply r159875 with fixes.

- Split pedantic driver flag test into separate test file, and XFAIL on cygwin,mingw32
- Fix bug in tablegen logic where a missing '{' caused errors to be included in -Wpedantic.

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@159892 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/tools/libclang/CXStoredDiagnostic.cpp b/tools/libclang/CXStoredDiagnostic.cpp
index 8284dc9..fa331de 100644
--- a/tools/libclang/CXStoredDiagnostic.cpp
+++ b/tools/libclang/CXStoredDiagnostic.cpp
@@ -66,13 +66,8 @@
       *Disable = createCXString("-ferror-limit=0");
     return createCXString("-ferror-limit=");
   }
-  
-  bool EnabledByDefault;
-  if (DiagnosticIDs::isBuiltinExtensionDiag(ID, EnabledByDefault) &&
-      !EnabledByDefault)
-    return createCXString("-pedantic");
 
-  return createCXString("");  
+  return createCXString("");
 }
 
 unsigned CXStoredDiagnostic::getCategory() const {