Fix bug spotted by Chris.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@40725 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/include/llvm/ADT/APSInt.h b/include/llvm/ADT/APSInt.h
index a2f0321..7e515da 100644
--- a/include/llvm/ADT/APSInt.h
+++ b/include/llvm/ADT/APSInt.h
@@ -85,17 +85,17 @@
   
   APSInt& extend(uint32_t width) {
     if (IsUnsigned)
-      *this = zext(width);
+      zext(width);
     else
-      *this = sext(width);
+      sext(width);
     return *this;
   }
   
   APSInt& extOrTrunc(uint32_t width) {
       if (IsUnsigned)
-        *this = zextOrTrunc(width);
+        zextOrTrunc(width);
       else
-        *this = sextOrTrunc(width);
+        sextOrTrunc(width);
       return *this;
   }