fixes #5241, fixes #5411 inherit from specialized generic typeRel problem (#5573)

tests/generics/tobjecttyperel.nim

@@ -0,0 +1,65 @@
+discard """
+  output: '''(peel: 0, color: 15)
+(color: 15)
+17
+(width: 0.0, taste: nil, color: 13)
+(width: 0.0, taste: nil, color: 15)
+cool'''
+"""
+
+# bug #5241
+type
+  BaseFruit[T] = object of RootObj
+    color: T
+    
+  MidLevel[T] = object of BaseFruit[T]
+  
+  Mango = object of MidLevel[int]
+    peel: int
+    
+  Peach[X, T, Y] = object of T
+    width: X
+    taste: Y
+    
+proc setColor[T](self: var BaseFruit[T]) =
+  self.color = 15
+
+proc setColor[T](self: var BaseFruit[T], c: int) =
+  self.color = c
+
+var c: Mango
+setColor(c)
+echo c
+
+var d: MidLevel[int]
+setColor(d)
+echo d
+
+type
+  FooBase[T] = ref object of RootRef
+    v: T
+  BarClient = ref object of FooBase[int]
+
+proc getColor[T](f: FooBase[T]): T = 17
+var b: BarClient
+echo getColor(b)
+
+var z: Peach[float64, BaseFruit[int], string]
+z.setColor(13)
+echo z
+
+z.setColor()
+echo z
+
+# bug #5411
+type
+  Foo[T] = ref object of RootRef
+    v: T
+  Bar = ref object of Foo[int]
+
+method m(o: RootRef) {.base.} = assert(false, "Abstract method called")
+method m[T](o: Foo[T]) = echo "cool"
+
+var v: Bar
+v.new()
+v.m() # Abstract method not called anymore