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/BasicAliasAnalysis.cpp b/lib/Analysis/BasicAliasAnalysis.cpp
index 74bee94..3ab18fd 100644
--- a/lib/Analysis/BasicAliasAnalysis.cpp
+++ b/lib/Analysis/BasicAliasAnalysis.cpp
@@ -206,14 +206,14 @@
     Value *CastOp = cast<CastInst>(V)->getOperand(0);
     unsigned OldWidth = Scale.getBitWidth();
     unsigned SmallWidth = CastOp->getType()->getPrimitiveSizeInBits();
-    Scale.trunc(SmallWidth);
-    Offset.trunc(SmallWidth);
+    Scale = Scale.trunc(SmallWidth);
+    Offset = Offset.trunc(SmallWidth);
     Extension = isa<SExtInst>(V) ? EK_SignExt : EK_ZeroExt;
 
     Value *Result = GetLinearExpression(CastOp, Scale, Offset, Extension,
                                         TD, Depth+1);
-    Scale.zext(OldWidth);
-    Offset.zext(OldWidth);
+    Scale = Scale.zext(OldWidth);
+    Offset = Offset.zext(OldWidth);
     
     return Result;
   }