PR5207: Change APInt methods trunc(), sext(), zext(), sextOrTrunc() and
zextOrTrunc(), and APSInt methods extend(), extOrTrunc() and new method
trunc(), to be const and to return a new value instead of modifying the
object in place.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@121120 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/Transforms/InstCombine/InstCombineMulDivRem.cpp b/lib/Transforms/InstCombine/InstCombineMulDivRem.cpp
index 1433f7b..6bce6a2 100644
--- a/lib/Transforms/InstCombine/InstCombineMulDivRem.cpp
+++ b/lib/Transforms/InstCombine/InstCombineMulDivRem.cpp
@@ -29,11 +29,11 @@
   uint32_t W = C1->getBitWidth();
   APInt LHSExt = C1->getValue(), RHSExt = C2->getValue();
   if (sign) {
-    LHSExt.sext(W * 2);
-    RHSExt.sext(W * 2);
+    LHSExt = LHSExt.sext(W * 2);
+    RHSExt = RHSExt.sext(W * 2);
   } else {
-    LHSExt.zext(W * 2);
-    RHSExt.zext(W * 2);
+    LHSExt = LHSExt.zext(W * 2);
+    RHSExt = RHSExt.zext(W * 2);
   }
   
   APInt MulExt = LHSExt * RHSExt;