kernel32: add more tests for FormatMessage{A,W}

[Dmitry Timoshkov]

"Louis Lenders" <xerox_xerox2000 at yahoo.co.uk> wrote:

> The attached tests show that this is true for "non-special" language-id's,
> but not for the special ones:
> (LANG_NEUTRAL, SUBLANG_NEUTRAL), (LANG_NEUTRAL, SUBLANG_DEFAULT),(LANG_NEUTRAL,
> SUBLANG_SYS_DEFAULT), and (DWORD)MAKELANGID(LANG_ENGLISH, SUBLANG_ENGLISH_US)
> 
> In the latter case the error is set to ERROR_MR_MID_NOT_FOUND

A couple of suggestions:
1. There is no point in testing last error if an API didn't fail
2. It would be helpful to simultaneously test return values and
last error for FindResource, which should have similar behaviour
(and the bug) to FormatMessage, and drop FormatMessageW tests.

-- 
Dmitry.