Revert "Merge pull request swiftlang#76396 from aschwaighofer/async_typed_throws_empty_errors"

This reverts commit ba8b7e4, reversing
changes made to 4693a47.

Author: aschwaighofer

lib/IRGen/GenCall.cpp

@@ -3030,10 +3030,7 @@ class AsyncCallEmission final : public CallEmission {
             IGF.IGM.getTypeInfo(silErrorTy).nativeReturnValueSchema(IGF.IGM);
 
         if (nativeSchema.requiresIndirect() ||
-            errorSchema.shouldReturnTypedErrorIndirectly() ||
-            (errorSchema.empty() && fnConv.hasIndirectSILResults())) { // direct empty typed errors are passed
-                                   // indirectly for compatibility with generic
-                                   // functions.
+            errorSchema.shouldReturnTypedErrorIndirectly()) {
           // Return the error indirectly.
           auto buf = IGF.getCalleeTypedErrorResultSlot(silErrorTy);
           Args[--LastArgWritten] = buf.getAddress();

test/IRGen/typed_throws.sil

@@ -458,61 +458,3 @@ bb6:
   %t = tuple()
   return %t : $()
 }
-
-sil @callee : $@convention(thin) @async (Int64) -> (@out (), @error Never) {
-bb0(%0 : $*(), %1: $Int64):
-  %17 = tuple ()
-  return %17 : $()
-}
-
-// CHECK: define{{.*}} swifttailcc void @callee(ptr {{.*}} %0, ptr swiftasync %1, i64 %2, ptr %3)
-
-// CHECK: define{{.*}} swifttailcc void @caller(ptr swiftasync %0) {{.*}} {
-// CHECK-NOT: define
-// CHECK: [[CTXT:%.*]] = call swiftcc ptr @swift_task_alloc
-// CHECK-NOT: define
-// CHECK: call {{.*}} @llvm.coro.suspend.async.sl_p0p0s(i32 256, ptr {{.*}}, ptr @__swift_async_resume_project_context, ptr @caller.0, ptr @callee, ptr undef, ptr [[CTXT]], i64 66, ptr %swifterror)
-
-sil @caller : $@convention(thin) @async () -> () {
-bb0:
-  %5 = integer_literal $Builtin.Int64, 66
-  %6 = struct $Int64 (%5 : $Builtin.Int64)
-  %9 = alloc_stack $()
-  %10 = function_ref @callee : $@convention(thin) @async (Int64) -> (@out (), @error Never)
-  try_apply %10(%9, %6) : $@convention(thin) @async (Int64) -> (@out (), @error Never), normal bb1, error bb2
-
-bb1(%12 : $()):
-  dealloc_stack %9 : $*()
-  %17 = tuple ()
-  return %17 : $()
-
-bb2(%19 : $Never):
-  unreachable
-}
-
-sil @callee2 : $@convention(thin) @async (Int) -> (Int, @error Never) {
-bb0(%0 :  $Int):
-  %5 = integer_literal $Builtin.Int64, 66
-  %6 = struct $Int (%5 : $Builtin.Int64)
-  return %6 : $Int
-}
-
-// CHECK: define{{.*}} swifttailcc void @callee2(ptr swiftasync %0, i64 %1)
-
-// CHECK: define{{.*}} swifttailcc void @caller2(ptr swiftasync %0)
-// CHECK: [[CTXT:%.*]] = call swiftcc ptr @swift_task_alloc
-// CHECK: @llvm.coro.suspend.async.sl_p0i64p0s({{.*}} ptr @callee2, ptr [[CTXT]], i64 67)
-sil @caller2 : $@convention(thin) @async () -> () {
-bb0:
-  %5 = integer_literal $Builtin.Int64, 67
-  %6 = struct $Int (%5 : $Builtin.Int64)
-  %10 = function_ref @callee2 : $@convention(thin) @async (Int) -> (Int, @error Never)
-  try_apply %10(%6) : $@convention(thin) @async (Int) -> (Int, @error Never), normal bb1, error bb2
-
-bb1(%12 : $Int):
-  %17 = tuple ()
-  return %17 : $()
-
-bb2(%19 : $Never):
-  unreachable
-}