Rename clang to clang-cc.

Tests and drivers updated, still need to shuffle dirs.

llvm-svn: 67602
diff --git a/clang/test/Sema/usual-float.c b/clang/test/Sema/usual-float.c
index 9c1977f..40c0bde 100644
--- a/clang/test/Sema/usual-float.c
+++ b/clang/test/Sema/usual-float.c
@@ -1,4 +1,4 @@
-// RUN: clang %s -fsyntax-only
+// RUN: clang-cc %s -fsyntax-only
 
 typedef float CGFloat;