ADT: Remove last implicit ilist iterator conversions, NFC

Some implicit ilist iterator conversions have crept back into Analysis,
Transforms, Hexagon, and llvm-stress.  This removes them.

I'll commit a patch immediately after this to disallow them (in a
separate patch so that it's easy to revert if necessary).

llvm-svn: 252371
diff --git a/llvm/lib/Analysis/ScalarEvolutionExpander.cpp b/llvm/lib/Analysis/ScalarEvolutionExpander.cpp
index b3b04ad..d763ca4 100644
--- a/llvm/lib/Analysis/ScalarEvolutionExpander.cpp
+++ b/llvm/lib/Analysis/ScalarEvolutionExpander.cpp
@@ -101,11 +101,11 @@
     if (isa<LandingPadInst>(IP) || isa<CleanupPadInst>(IP)) {
       ++IP;
     } else if (auto *TPI = dyn_cast<TerminatePadInst>(IP)) {
-      IP = TPI->getUnwindDest()->getFirstNonPHI();
+      IP = TPI->getUnwindDest()->getFirstNonPHI()->getIterator();
     } else if (auto *CEPI = dyn_cast<CatchEndPadInst>(IP)) {
-      IP = CEPI->getUnwindDest()->getFirstNonPHI();
+      IP = CEPI->getUnwindDest()->getFirstNonPHI()->getIterator();
     } else if (auto *CEPI = dyn_cast<CleanupEndPadInst>(IP)) {
-      IP = CEPI->getUnwindDest()->getFirstNonPHI();
+      IP = CEPI->getUnwindDest()->getFirstNonPHI()->getIterator();
     } else if (isa<CatchPadInst>(IP)) {
       IP = MustDominate->getFirstInsertionPt();
     } else {