Treat list-initialization of scalars as a first-class citizen in C++11.
Allow empty initializer lists for scalars, which mean value-initialization.
Constant evaluation for single-element and empty initializer lists for scalars.
Codegen for empty initializer lists for scalars.
Test case comes in next commit.

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@140459 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/Sema/SemaInit.cpp b/lib/Sema/SemaInit.cpp
index 7c27e6f..2e4b236 100644
--- a/lib/Sema/SemaInit.cpp
+++ b/lib/Sema/SemaInit.cpp
@@ -877,11 +877,12 @@
                                       InitListExpr *StructuredList,
                                       unsigned &StructuredIndex) {
   if (Index >= IList->getNumInits()) {
-    // FIXME: Allowed in C++11.
-    if (!VerifyOnly)
-      SemaRef.Diag(IList->getLocStart(), diag::err_empty_scalar_initializer)
-        << IList->getSourceRange();
-    hadError = true;
+    if (!SemaRef.getLangOptions().CPlusPlus0x) {
+      if (!VerifyOnly)
+        SemaRef.Diag(IList->getLocStart(), diag::err_empty_scalar_initializer)
+          << IList->getSourceRange();
+      hadError = true;
+    }
     ++Index;
     ++StructuredIndex;
     return;