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/Frontend/PCHReaderStmt.cpp b/lib/Frontend/PCHReaderStmt.cpp
index 16c0e79..6b97e61 100644
--- a/lib/Frontend/PCHReaderStmt.cpp
+++ b/lib/Frontend/PCHReaderStmt.cpp
@@ -460,6 +460,8 @@
 unsigned PCHStmtReader::VisitCastExpr(CastExpr *E) {
   VisitExpr(E);
   E->setSubExpr(cast<Expr>(StmtStack.back()));
+  E->setCastKind((CastExpr::CastKind)Record[Idx++]);
+
   return 1;
 }