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

lib/Support/StringRef.cpp

@@ -371,7 +371,7 @@ bool StringRef::getAsInteger(unsigned Radix, APInt &Result) const {
   if (BitWidth < Result.getBitWidth())
     BitWidth = Result.getBitWidth(); // don't shrink the result
   else
-    Result.zext(BitWidth);
+    Result = Result.zext(BitWidth);
 
   APInt RadixAP, CharAP; // unused unless !IsPowerOf2Radix
   if (!IsPowerOf2Radix) {