RFA: Tweak test for fileio support

[Benjamin Kosnik]

> Many of the libstdc++ file I/O tests fail for mips-sim-idt{32,64}.
> The IDT monitor apparently provides callbacks for open and close,
> which the gdb simulator emulates as full semihosted calls.  This is
> enough to pass the open ("." ...) test in check_v3_target_fileio.
> However, the monitor doesn't provide callbacks for lseek or *stat,
> so libgloss provides dummy implementations that cause most real file
> I/O tests fail.

Got it.


> libstdc++-v3/
> 	* testsuite/lib/libstdc++.exp (check_v3_target_fileio): Test
> lseek.

This is OK.

-benjamin