Add a CastKind enum to CastExpr. Right now it's not used for much but it will be :)

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@77650 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/Sema/SemaDecl.cpp b/lib/Sema/SemaDecl.cpp
index 01875bb..4c310aa 100644
--- a/lib/Sema/SemaDecl.cpp
+++ b/lib/Sema/SemaDecl.cpp
@@ -5169,7 +5169,9 @@
     
     // Adjust the Expr initializer and type.
     if (ECD->getInitExpr())
-      ECD->setInitExpr(new (Context) ImplicitCastExpr(NewTy, ECD->getInitExpr(), 
+      ECD->setInitExpr(new (Context) ImplicitCastExpr(NewTy, 
+                                                      CastExpr::CK_Unknown, 
+                                                      ECD->getInitExpr(), 
                                                       /*isLvalue=*/false));
     if (getLangOptions().CPlusPlus)
       // C++ [dcl.enum]p4: Following the closing brace of an