[PlaceSafepoints] Cleanup InsertSafepointPoll function

While working on another change, I noticed that the naming in this function was mildly deceptive.  While fixing that, I took the oppurtunity to modernize some of the code.  NFC intended.



git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@238252 91177308-0d34-0410-b5e6-96231b3b80d8

lib/IR/BasicBlock.cpp

@@ -117,6 +117,10 @@ const Module *BasicBlock::getModule() const {
   return getParent()->getParent();
 }
 
+Module *BasicBlock::getModule() {
+  return getParent()->getParent();
+}
+
 TerminatorInst *BasicBlock::getTerminator() {
   if (InstList.empty()) return nullptr;
   return dyn_cast<TerminatorInst>(&InstList.back());