Mass rename C1x references to C11. The name hasn't proliferated like "C++0x" so this patch is surprisingly small.

Also drop -Wc1x-extensions in favor of -Wc11-extensions. I don't think we need to keep this around for compatibility.

llvm-svn: 147221
diff --git a/clang/lib/AST/ExprClassification.cpp b/clang/lib/AST/ExprClassification.cpp
index f5ee3e5..60e6f96 100644
--- a/clang/lib/AST/ExprClassification.cpp
+++ b/clang/lib/AST/ExprClassification.cpp
@@ -247,7 +247,7 @@
   case Expr::ParenExprClass:
     return ClassifyInternal(Ctx, cast<ParenExpr>(E)->getSubExpr());
 
-    // C1X 6.5.1.1p4: [A generic selection] is an lvalue, a function designator,
+    // C11 6.5.1.1p4: [A generic selection] is an lvalue, a function designator,
     // or a void expression if its result expression is, respectively, an
     // lvalue, a function designator, or a void expression.
   case Expr::GenericSelectionExprClass: