i965: Make intelEmitCopyBlit not truncate large strides.

i965: Make intelEmitCopyBlit not truncate large strides.

When trying to blit larger tiled surfaces, the pitch can be larger than
32768 bytes, which means it won't fit in a GLshort.  Passing it in will
truncate the stride to 0, which has...surprising results.

The pitch can be up to 32,768 DWords, or 128kB.  We measure it in bytes,
but divide by 4 when programming it.  So we need to handle values up to
131,072.  Switch from GLshort to int32_t to avoid the truncation.

Fixes GL45-CTS.gtf30.GL3Tests.depth_texture.depth_texture_copyteximage
at widths greater than 8192.

v2: Use int32_t as negative values can be used (Jason).

Cc: "17.0" <mesa-stable@lists.freedesktop.org>
Signed-off-by: Kenneth Graunke <kenneth@whitecape.org>
Reviewed-by: Jason Ekstrand <jason@jlekstrand.net>