IC: added basic test case for methods (#17679)

* IC: added basic test case for methods

* IC: better methods test

tests/ic/mbaseobj.nim

@@ -0,0 +1,7 @@
+
+type
+  Base* = ref object of RootObj
+    s*: string
+
+method m*(b: Base) {.base.} =
+  echo "Base ", b.s

tests/ic/tmethods.nim

@@ -0,0 +1,28 @@
+discard """
+  output: '''Base abc'''
+"""
+
+import mbaseobj
+
+var c = Base(s: "abc")
+m c
+
+#!EDIT!#
+
+discard """
+  output: '''Base abc
+Inherited abc'''
+"""
+
+import mbaseobj
+
+type
+  Inherited = ref object of Base
+
+method m(i: Inherited) =
+  procCall m(Base i)
+  echo "Inherited ", i.s
+
+var c = Inherited(s: "abc")
+m c
+