fixes #25227; crash when codegen user-defined tuple iterate (#25228)

fixes #25227

(cherry picked from commit 39be9b9)

Author: litlighilit

compiler/ccgexprs.nim

@@ -852,7 +852,7 @@ proc genTupleElem(p: BProc, e: PNode, d: var TLoc) =
   var
     i: int = 0
   var a: TLoc = initLocExpr(p, e[0])
-  let tupType = a.t.skipTypes(abstractInst+{tyVar})
+  let tupType = a.t.skipTypes(abstractInst+{tyVar}+tyUserTypeClasses) # ref #25227
   assert tupType.kind == tyTuple
   d.inheritLocation(a)
   discard getTypeDesc(p.module, a.t) # fill the record's fields.loc

compiler/jsgen.nim

@@ -1371,7 +1371,8 @@ proc genFieldAddr(p: PProc, n: PNode, r: var TCompRes) =
   r.typ = etyBaseIndex
   let b = if n.kind == nkHiddenAddr: n[0] else: n
   gen(p, b[0], a)
-  if skipTypes(b[0].typ, abstractVarRange).kind == tyTuple:
+  if skipTypes(b[0].typ, abstractVarRange + tyTypeClasses).kind == tyTuple:
+    # ref #25227 about `+ tyTypeClasses`
     r.res = makeJSString("Field" & $getFieldPosition(p, b[1]))
   else:
     if b[1].kind != nkSym: internalError(p.config, b[1].info, "genFieldAddr")