Revert "[OpenCL] Add supported OpenCL extensions to target info."

Revert r269431 due to build failure caused by warning msg:

  llvm/tools/clang/lib/Basic/Targets.cpp:2090:9: error: 'setSupportedOpenCLOpts' overrides a member function but is not marked 'override' [-Werror,-Winconsistent-missing-override]
   void setSupportedOpenCLOpts() {

llvm-svn: 269435
diff --git a/clang/lib/Sema/Sema.cpp b/clang/lib/Sema/Sema.cpp
index 35e303e..d8d10b6 100644
--- a/clang/lib/Sema/Sema.cpp
+++ b/clang/lib/Sema/Sema.cpp
@@ -207,14 +207,8 @@
     addImplicitTypedef("size_t", Context.getSizeType());
   }
 
-  // Initialize predefined OpenCL types and supported optional core features.
+  // Initialize predefined OpenCL types.
   if (getLangOpts().OpenCL) {
-#define OPENCLEXT(Ext) \
-     if (Context.getTargetInfo().getSupportedOpenCLOpts().is_##Ext##_supported_core( \
-         getLangOpts().OpenCLVersion)) \
-       getOpenCLOptions().Ext = 1;
-#include "clang/Basic/OpenCLExtensions.def"
-
     addImplicitTypedef("sampler_t", Context.OCLSamplerTy);
     addImplicitTypedef("event_t", Context.OCLEventTy);
     if (getLangOpts().OpenCLVersion >= 200) {