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/Analysis/ConstantFolding.cpp b/lib/Analysis/ConstantFolding.cpp
index 70ee9dd..68a55b6 100644
--- a/lib/Analysis/ConstantFolding.cpp
+++ b/lib/Analysis/ConstantFolding.cpp
@@ -610,10 +610,8 @@
   APInt BasePtr(BitWidth, 0);
   if (ConstantExpr *CE = dyn_cast<ConstantExpr>(Ptr))
     if (CE->getOpcode() == Instruction::IntToPtr)
-      if (ConstantInt *Base = dyn_cast<ConstantInt>(CE->getOperand(0))) {
-        BasePtr = Base->getValue();
-        BasePtr.zextOrTrunc(BitWidth);
-      }
+      if (ConstantInt *Base = dyn_cast<ConstantInt>(CE->getOperand(0)))
+        BasePtr = Base->getValue().zextOrTrunc(BitWidth);
   if (Ptr->isNullValue() || BasePtr != 0) {
     Constant *C = ConstantInt::get(Ptr->getContext(), Offset+BasePtr);
     return ConstantExpr::getIntToPtr(C, ResultTy);