[CoroSplit] Fix use-after-free related to coro.suspend (#156572)

Fix #156444

Author: NewSigma

llvm/lib/Transforms/Coroutines/Coroutines.cpp

@@ -356,9 +356,9 @@ void coro::Shape::invalidateCoroutine(
     // present.
     for (AnyCoroSuspendInst *CS : CoroSuspends) {
       CS->replaceAllUsesWith(PoisonValue::get(CS->getType()));
-      CS->eraseFromParent();
       if (auto *CoroSave = CS->getCoroSave())
         CoroSave->eraseFromParent();
+      CS->eraseFromParent();
     }
     CoroSuspends.clear();
 

llvm/test/Transforms/Coroutines/coro-split-invalid.ll

@@ -0,0 +1,14 @@
+; NOTE: Assertions have been autogenerated by utils/update_test_checks.py UTC_ARGS: --version 5
+; Tests that coro-split correctly invalidate bad coroutines
+; RUN: opt < %s -passes='cgscc(coro-split)' -S | FileCheck %s
+
+define void @pr156444() presplitcoroutine {
+; CHECK-LABEL: define void @pr156444(
+; CHECK-SAME: ) #[[ATTR0:[0-9]+]] {
+; CHECK-NEXT:  [[ENTRY:.*:]]
+; CHECK-NEXT:    ret void
+;
+entry:
+  %0 = call i8 @llvm.coro.suspend(token none, i1 false)
+  ret void
+}