Fix tryRewriteToPartialApplyStack to handle undef

lib/SILOptimizer/Mandatory/ClosureLifetimeFixup.cpp

@@ -895,10 +895,11 @@ static SILValue tryRewriteToPartialApplyStack(
     SILBuilderWithScope builder(std::next(destroy->getIterator()));
     // This getCapturedArg hack attempts to perfectly compensate for all the
     // other hacks involved in gathering new arguments above.
+    // argValue may be 'undef'
     auto getArgToDestroy = [&](SILValue argValue) -> SILValue {
       // A MoveOnlyWrapperToCopyableValueInst may produce a trivial value. Be
       // careful not to emit an extra destroy of the original.
-      if (argValue->getType().isTrivial(argValue->getFunction()))
+      if (argValue->getType().isTrivial(destroy->getFunction()))
         return SILValue();
 
       // We may have inserted a new begin_borrow->moveonlywrapper_to_copyvalue

test/SILOptimizer/closure-lifetime-fixup.sil

@@ -348,3 +348,36 @@ bb0(%0 : @noImplicitCopy @_eagerMove $Int):
   dealloc_stack %1 : $*@moveOnly Int
   return %14 : $Int
 }
+
+struct _UnsafeContinuation<T, R> {}
+
+sil @testCapturedUndefClosure : $@convention(thin) @substituted <τ_0_0> (_UnsafeContinuation<τ_0_0, any Error>, Int) -> () for <Int>
+sil @testCapturedUndefTakeClosure : $@convention(thin) <τ_0_0> (@guaranteed @noescape @callee_guaranteed @substituted <τ_0_0> (_UnsafeContinuation<τ_0_0, any Error>) -> () for <τ_0_0>) -> (@out τ_0_0, @error any Error)
+
+// insertDestroyOfCapturedArguments should not crash on 'undef'
+//
+// CHECK-LABEL: sil hidden [ossa] @testCapturedUndef : $@convention(thin) (Int) -> (Int, @error any Error) {
+// CHECK: partial_apply [callee_guaranteed] [on_stack] %{{.*}}(undef)
+// CHECK-LABEL: } // end sil function 'testCapturedUndef'
+sil hidden [ossa] @testCapturedUndef : $@convention(thin) (Int) -> (Int, @error any Error) {
+bb0(%0 : $Int):
+  %5 = alloc_stack $Int
+  %6 = function_ref @testCapturedUndefClosure : $@convention(thin) @substituted <τ_0_0> (_UnsafeContinuation<τ_0_0, any Error>, Int) -> () for <Int>
+  %7 = partial_apply [callee_guaranteed] %6(undef) : $@convention(thin) @substituted <τ_0_0> (_UnsafeContinuation<τ_0_0, any Error>, Int) -> () for <Int>
+  %8 = convert_escape_to_noescape [not_guaranteed] %7 : $@callee_guaranteed @substituted <τ_0_0> (_UnsafeContinuation<τ_0_0, any Error>) -> () for <Int> to $@noescape @callee_guaranteed @substituted <τ_0_0> (_UnsafeContinuation<τ_0_0, any Error>) -> () for <Int>
+  destroy_value %7 : $@callee_guaranteed @substituted <τ_0_0> (_UnsafeContinuation<τ_0_0, any Error>) -> () for <Int>
+
+  %10 = function_ref @testCapturedUndefTakeClosure : $@convention(thin) <τ_0_0> (@guaranteed @noescape @callee_guaranteed @substituted <τ_0_0> (_UnsafeContinuation<τ_0_0, any Error>) -> () for <τ_0_0>) -> (@out τ_0_0, @error any Error)
+  try_apply %10<Int>(%5, %8) : $@convention(thin) <τ_0_0> (@guaranteed @noescape @callee_guaranteed @substituted <τ_0_0> (_UnsafeContinuation<τ_0_0, any Error>) -> () for <τ_0_0>) -> (@out τ_0_0, @error any Error), normal bb1, error bb2
+
+bb1(%12 : $()):
+  destroy_value %8 : $@noescape @callee_guaranteed @substituted <τ_0_0> (_UnsafeContinuation<τ_0_0, any Error>) -> () for <Int>
+  %15 = load [trivial] %5 : $*Int
+  dealloc_stack %5 : $*Int
+  return %15 : $Int
+
+bb2(%19 : @owned $any Error):
+  destroy_value %8 : $@noescape @callee_guaranteed @substituted <τ_0_0> (_UnsafeContinuation<τ_0_0, any Error>) -> () for <Int>
+  dealloc_stack %5 : $*Int
+  throw %19 : $any Error
+}