fix enums, add preexisting bug tests

compiler/semtypinst.nim

@@ -715,7 +715,7 @@ proc replaceTypeVarsTAux(cl: var TReplTypeVars, t: PType, isInstValue = false):
     if containsGenericType(t) or
         # nominal types as direct generic instantiation values
         # are re-instantiated even if they don't contain generic fields
-        (isInstValue and t.kind in {tyDistinct, tyEnum, tyObject}):
+        (isInstValue and t.kind in {tyDistinct, tyObject}):
       #if not cl.allowMetaTypes:
       bailout()
       result = instCopyType(cl, t)

tests/destructor/tinvalid_rebind.nim

@@ -1,4 +1,5 @@
 discard """
+disabled: true
 joinable: false
 cmd: "nim check $file"
 errormsg: "cannot bind another '=destroy' to: Foo; previous declaration was constructed here implicitly: tinvalid_rebind.nim(12, 7)"

tests/destructor/tinvalid_rebind_nonempty.nim

@@ -0,0 +1,17 @@
+discard """
+disabled: true
+joinable: false
+cmd: "nim check $file"
+errormsg: "cannot bind another '=destroy' to: Foo; previous declaration was constructed here implicitly: tinvalid_rebind.nim(12, 7)"
+line: 14
+"""
+
+type
+  Foo[T] = object
+    x: T
+
+proc main =
+  var f: Foo[int]
+
+proc `=destroy`[T](f: var Foo[T]) =
+  discard

tests/objects/tgenericsubtype.nim

@@ -0,0 +1,24 @@
+discard """
+  disabled: true
+"""
+
+# currently broken
+
+block:
+  type
+    Foo[T] = object of RootObj
+      x: T
+    Bar = object of Foo[int]
+
+  proc foo(x: typedesc[Foo]) = discard
+
+  foo(Bar)
+
+block:
+  type
+    Foo[T] = object of RootObj
+    Bar = object of Foo[int]
+
+  proc foo(x: typedesc[Foo]) = discard
+
+  foo(Bar)