* dlfcn.cc (set_dl_error): Drop useless __stdcall.
	(check_path_access): Ditto.  Drop FE_CWD from call to find_exec.
	(gfpod_helper): Call path_conv::check for all paths containing a dir
	separator to more closely follow the Linux search algorithm.
	(get_full_path_of_dll): Drop useless __stdcall.
	(dlopen): Simplify RTLD_NOLOAD case by calling GetModuleHandleEx
	instead of GetModuleHandle/LoadLibrary.
	* dlfcn.cc (gfpod_helper): Only check for POSIX dir separator, same as
	in get_full_path_of_dll.