Update for LLVM function name change.

llvm-svn: 257802
diff --git a/clang/lib/AST/ExprConstant.cpp b/clang/lib/AST/ExprConstant.cpp
index fa652ba..eaa61ea 100644
--- a/clang/lib/AST/ExprConstant.cpp
+++ b/clang/lib/AST/ExprConstant.cpp
@@ -5135,7 +5135,7 @@
     }
 
     // The offset must also have the correct alignment.
-    if (OffsetResult.Offset.RoundUpToAlignment(Align) != OffsetResult.Offset) {
+    if (OffsetResult.Offset.alignTo(Align) != OffsetResult.Offset) {
       Result.Designator.setInvalid();
       APSInt Offset(64, false);
       Offset = OffsetResult.Offset.getQuantity();