Address comments from Doug - Add a Sema::SemaRef.BuildBlockPointerType and use it.

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@73264 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/Sema/SemaTemplateDeduction.cpp b/lib/Sema/SemaTemplateDeduction.cpp
index 48e38dd..4bbfd04 100644
--- a/lib/Sema/SemaTemplateDeduction.cpp
+++ b/lib/Sema/SemaTemplateDeduction.cpp
@@ -497,6 +497,8 @@
                                      Info, Deduced);
     }
 
+    //     (clang extension)
+    //
     //     type(^)(T) 
     //     T(^)() 
     //     T(^)(T)