cgen,checker: cleanup resolve_comptime_args

[felipensp]

• Unify code for checker and cgen on generic_resolver.v
• Rename to simply resolve_args
• Moved resolve_fn_generic_args, get_generic_array_element_type and get_generic_array_fixed_element_type to generic_resolver.v

_{Huly®: V_0.6-21768}