fixes sink regression for ORC; ref #23354 (#23359)

ref #23354

The new move analyzer requires types that have the tfAsgn flag
(otherwise `lastRead` will return true); tfAsgn is included when the
destructor is not trival. But it should consider the assignement for
objects in this case because objects might have a trival destructors but
it's the assignement that matters when it is passed to sink parameters.

compiler/injectdestructors.nim

@@ -163,7 +163,8 @@ proc isLastReadImpl(n: PNode; c: var Con; scope: var Scope): bool =
     result = false
 
 proc isLastRead(n: PNode; c: var Con; s: var Scope): bool =
-  if not hasDestructor(c, n.typ): return true
+  # bug #23354; an object type could have a non-trival assignements when it is passed to a sink parameter
+  if not hasDestructor(c, n.typ) and (n.typ.kind != tyObject or isTrival(getAttachedOp(c.graph, n.typ, attachedAsgn))): return true
 
   let m = skipConvDfa(n)
   result = (m.kind == nkSym and sfSingleUsedTemp in m.sym.flags) or

compiler/liftdestructors.nim

@@ -1252,7 +1252,7 @@ proc inst(g: ModuleGraph; c: PContext; t: PType; kind: TTypeAttachedOp; idgen: I
     else:
       localError(g.config, info, "unresolved generic parameter")
 
-proc isTrival(s: PSym): bool {.inline.} =
+proc isTrival*(s: PSym): bool {.inline.} =
   s == nil or (s.ast != nil and s.ast[bodyPos].len == 0)
 
 proc createTypeBoundOps(g: ModuleGraph; c: PContext; orig: PType; info: TLineInfo;

tests/destructor/tsink.nim

@@ -0,0 +1,16 @@
+discard """
+  matrix: "--mm:arc"
+"""
+
+type AnObject = object of RootObj
+  value*: int
+
+proc mutate(shit: sink AnObject) =
+  shit.value = 1
+
+proc foo = # bug #23359
+  var bar = AnObject(value: 42)
+  mutate(bar)
+  doAssert bar.value == 42
+
+foo()