do not give "has no field" warnings in matcher.ml, instead generate FDynamic (fixed issue #1619)

matcher.ml

@@ -855,7 +855,7 @@ let rec st_to_texpr mctx st = match st.st_def with
 	| SVar v -> mk (TLocal v) v.v_type st.st_pos
 	| SField (sts,f) ->
 		let e = st_to_texpr mctx sts in
-		let fa = try quick_field e.etype f with Not_found -> raise (Error ((Unify [has_no_field e.etype f]), sts.st_pos)) in
+		let fa = try quick_field e.etype f with Not_found -> FDynamic f in
 		mk (TField(e,fa)) st.st_type st.st_pos
 	| SArray (sts,i) -> mk (TArray(st_to_texpr mctx sts,mk_const mctx.ctx st.st_pos (TInt (Int32.of_int i)))) st.st_type st.st_pos
 	| STuple (st,_,_) -> st_to_texpr mctx st