Recommit r289979 [OpenCL] Allow disabling types and declarations associated with extensions

Fixed undefined behavior due to cast integer to bool in initializer list.

llvm-svn: 290056
diff --git a/clang/lib/Frontend/InitPreprocessor.cpp b/clang/lib/Frontend/InitPreprocessor.cpp
index 31340e0..47881b1 100644
--- a/clang/lib/Frontend/InitPreprocessor.cpp
+++ b/clang/lib/Frontend/InitPreprocessor.cpp
@@ -988,7 +988,7 @@
   // OpenCL definitions.
   if (LangOpts.OpenCL) {
 #define OPENCLEXT(Ext) \
-    if (TI.getSupportedOpenCLOpts().is_##Ext##_supported( \
+    if (TI.getSupportedOpenCLOpts().isSupported(#Ext, \
         LangOpts.OpenCLVersion)) \
       Builder.defineMacro(#Ext);
 #include "clang/Basic/OpenCLExtensions.def"