Rename clang to clang-cc.

Tests and drivers updated, still need to shuffle dirs.

llvm-svn: 67602
diff --git a/clang/test/Sema/struct-compat.c b/clang/test/Sema/struct-compat.c
index 489ff47..35d8fb1 100644
--- a/clang/test/Sema/struct-compat.c
+++ b/clang/test/Sema/struct-compat.c
@@ -1,4 +1,4 @@
-/* RUN: clang %s -fsyntax-only -pedantic -verify
+/* RUN: clang-cc %s -fsyntax-only -pedantic -verify
  */
 
 extern struct {int a;} x; // expected-note {{previous definition is here}}