Add tests for MREMAP_MAYMOVE and MREMAP_FIXED. On Linux, also test
MREMAP_DONTUNMAP.
Signed-off-by: H.J. Lu <hjl.tools@gmail.com>
Reviewed-by: Adhemerval Zanella <adhemerval.zanella@linaro.org>
(cherry picked from commit ff0320bec2810192d453c579623482fab87bfa01)