Implement initialization of a reference (C++ [dcl.init.ref]) as part
of copy initialization. Other pieces of the puzzle:

  - Try/Perform-ImplicitConversion now handles implicit conversions
    that don't involve references.
  - Try/Perform-CopyInitialization uses
    CheckSingleAssignmentConstraints for C. PerformCopyInitialization
    is now used for all argument passing and returning values from a
    function.
  - Diagnose errors with declaring references and const values without
    an initializer. (Uses a new Action callback, ActOnUninitializedDecl).
  
We do not yet have implicit conversion sequences for reference
binding, which means that we don't have any overloading support for
reference parameters yet.



git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@58353 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/Parse/ParseDecl.cpp b/lib/Parse/ParseDecl.cpp
index 6bcb90b..243a15f 100644
--- a/lib/Parse/ParseDecl.cpp
+++ b/lib/Parse/ParseDecl.cpp
@@ -310,6 +310,8 @@
                                               &Exprs[0], Exprs.size(),
                                               &CommaLocs[0], RParenLoc);
       }
+    } else {
+      Actions.ActOnUninitializedDecl(LastDeclInGroup);
     }
     
     // If we don't have a comma, it is either the end of the list (a ';') or an