Reactivate mbsrtowcs() tests, as those do work, now.

Fix build warnings with gcc4.

Added tests, exposing problems in wcsrtombs() and mbsrtowcs().

Drop a couple of mbsrtowcs() tests that can't work on Haiku.

* Our mbstate_t just references a corresponding ICU converter, but
does not actually contain its state. So a mere copying of the mbstate
won't duplicate the converter's intrinsic state, which means that
restarting with the copied state won't work.
If have experimented with cloning the converter into the mbstate_t,
but I was unable to get that to work, either. Apparently, the state
of the converter isn't cloned (but just the converter's settings
and data).

Add gnulib-test-mbsrtowcs.c in order to test mbsrtowcs()

* the test exposes problems in our current (glibc's) implementation
of mbsrtowcs()

Reactivate mbsrtowcs() tests, as those do work, now.

Fix build warnings with gcc4.

Added tests, exposing problems in wcsrtombs() and mbsrtowcs().

Drop a couple of mbsrtowcs() tests that can't work on Haiku.

* Our mbstate_t just references a corresponding ICU converter, but
does not actually contain its state. So a mere copying of the mbstate
won't duplicate the converter's intrinsic state, which means that
restarting with the copied state won't work.
If have experimented with cloning the converter into the mbstate_t,
but I was unable to get that to work, either. Apparently, the state
of the converter isn't cloned (but just the converter's settings
and data).

Add gnulib-test-mbsrtowcs.c in order to test mbsrtowcs()

* the test exposes problems in our current (glibc's) implementation
of mbsrtowcs()