Convert a few expression actions to smart pointers.
These actions are extremely widely used (identifier expressions and literals); still no performance regression.

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@62468 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/Parse/ParseDecl.cpp b/lib/Parse/ParseDecl.cpp
index 319c03e..456acbe 100644
--- a/lib/Parse/ParseDecl.cpp
+++ b/lib/Parse/ParseDecl.cpp
@@ -2105,7 +2105,7 @@
   } else if (Tok.getKind() == tok::numeric_constant &&
              GetLookAheadToken(1).is(tok::r_square)) {
     // [4] is very common.  Parse the numeric constant expression.
-    OwningExprResult ExprRes(Actions, Actions.ActOnNumericConstant(Tok));
+    OwningExprResult ExprRes(Actions.ActOnNumericConstant(Tok));
     ConsumeToken();
 
     MatchRHSPunctuation(tok::r_square, StartLoc);