Revert "fixes #13378 [backport] (#13392)"

This reverts commit 14e1f82f42.

compiler/sigmatch.nim

@@ -1945,8 +1945,6 @@ proc localConvMatch(c: PContext, m: var TCandidate, f, a: PType,
 
   if result != nil:
     if result.typ == nil: return nil
-    # bug #13378, ensure we produce a real generic instantiation:
-    result = c.semExpr(c, call)
     # resulting type must be consistent with the other arguments:
     var r = typeRel(m, f.sons[0], result.typ)
     if r < isGeneric: return nil

tests/generics/tgeneric0.nim

@@ -4,7 +4,6 @@ discard """
 0
 float32
 float32
-(name: "Resource 1", readers: ..., writers: ...)
 '''
 """
 
@@ -125,18 +124,3 @@ block tgeneric5:
     echo T
 
   bar(0.0'f32)
-
-# bug #13378
-
-type
-  Resource = ref object of RootObj
-    name: string
-    readers, writers: seq[RenderTask]
-
-  RenderTask = ref object
-    name: string
-
-var res = Resource(name: "Resource 1")
-
-(proc (r: typeof(res)) =
-   echo r[])(res)