fixes #23627; Simple destructor code gives invalid C (#23631)

fixes #23627

```nim
type
  TestObj = object of RootObj

  TestTestObj = object of RootObj
    testo: TestObj

proc `=destroy`(x: TestTestObj) =
  echo "Destructor for TestTestObj"

proc testCaseT() =
  echo "\nTest Case T"
  let tt1 {.used.} = TestTestObj(testo: TestObj())
```

When generating const object fields, it's likely that
we need to generate type infos for the object, which may be an object
with
custom hooks. We need to generate potential consts in the hooks first.

https://github.com/nim-lang/Nim/pull/20433 changed the semantics of
initialization. It should evaluate`BracedInit` first.

1 files changed, 29 insertions, 5 deletions

diff --git a/tests/arc/tarcmisc.nim b/tests/arc/tarcmisc.nim
index aef230334..88582303d 100644
--- a/tests/arc/tarcmisc.nim
+++ b/tests/arc/tarcmisc.nim
@@ -1,5 +1,6 @@
 discard """
   output: '''
+Destructor for TestTestObj
 =destroy called
 123xyzabc
 destroyed: false
@@ -36,9 +37,33 @@ destroying variable: 20
 destroying variable: 10
 closed
 '''
-  cmd: "nim c --gc:arc --deepcopy:on -d:nimAllocPagesViaMalloc $file"
+  cmd: "nim c --mm:arc --deepcopy:on -d:nimAllocPagesViaMalloc $file"
 """
 
+block: # bug #23627
+  type
+    TestObj = object of RootObj
+
+    Test2 = object of RootObj
+      foo: TestObj
+
+    TestTestObj = object of RootObj
+      shit: TestObj
+
+  proc `=destroy`(x: TestTestObj) =
+    echo "Destructor for TestTestObj"
+    let test = Test2(foo: TestObj())
+
+  proc testCaseT() =
+    let tt1 {.used.} = TestTestObj(shit: TestObj())
+
+
+  proc main() =
+    testCaseT()
+
+  main()
+
+
 # bug #9401
 
 type
@@ -46,13 +71,12 @@ type
     len: int
     data: ptr UncheckedArray[float]
 
-proc `=destroy`*(m: var MyObj) =
+proc `=destroy`*(m: MyObj) =
 
   echo "=destroy called"
 
   if m.data != nil:
     deallocShared(m.data)
-    m.data = nil
 
 type
   MyObjDistinct = distinct MyObj
@@ -104,7 +128,7 @@ bbb("123")
 type Variable = ref object
   value: int
 
-proc `=destroy`(self: var typeof(Variable()[])) =
+proc `=destroy`(self: typeof(Variable()[])) =
   echo "destroying variable: ",self.value
 
 proc newVariable(value: int): Variable =
@@ -158,7 +182,7 @@ type
   B = ref object of A
     x: int
 
-proc `=destroy`(x: var AObj) =
+proc `=destroy`(x: AObj) =
   close(x.io)
   echo "closed"