[CUDA] Rename cuda_builtin_vars.h to __clang_cuda_builtin_vars.h.

Summary: This matches the idiom we use for our other CUDA wrapper headers.

Reviewers: tra

Subscribers: beanz, mgorny, cfe-commits

Differential Revision: https://reviews.llvm.org/D24978

llvm-svn: 283679
diff --git a/clang/lib/Frontend/CompilerInvocation.cpp b/clang/lib/Frontend/CompilerInvocation.cpp
index 0dd05b5..cf39f35 100644
--- a/clang/lib/Frontend/CompilerInvocation.cpp
+++ b/clang/lib/Frontend/CompilerInvocation.cpp
@@ -2012,9 +2012,10 @@
   // enabled for Microsoft Extensions or Borland Extensions, here.
   //
   // FIXME: __declspec is also currently enabled for CUDA, but isn't really a
-  // CUDA extension, however it is required for supporting cuda_builtin_vars.h,
-  // which uses __declspec(property). Once that has been rewritten in terms of
-  // something more generic, remove the Opts.CUDA term here.
+  // CUDA extension. However, it is required for supporting
+  // __clang_cuda_builtin_vars.h, which uses __declspec(property). Once that has
+  // been rewritten in terms of something more generic, remove the Opts.CUDA
+  // term here.
   Opts.DeclSpecKeyword =
       Args.hasFlag(OPT_fdeclspec, OPT_fno_declspec,
                    (Opts.MicrosoftExt || Opts.Borland || Opts.CUDA));