i965: fix noop_scissor range issue on width/height
i965: fix noop_scissor range issue on width/height

If scissor X or Y was set to a negative value then the previous
code might have indicated noop scissors when the scissor range
actually was masking a portion of the framebuffer.

Since fb->_Xmin, _Xmax, _Ymin and _Ymax take scissors into
account, we can use these to test for a noop scissor.

Cc: 59f39c0db42d4479a46b02d4d2bc11120e37bb44@lists.freedesktop.org
Reviewed-by: Matt Turner <789b315743a28dd066a4ba1459c35951c291d8a6@gmail.com>
Signed-off-by: Jordan Justen <a79006884ba9cf5f4f7fcbb92a15b208780d8c97@intel.com>

metora/MesaGLSLCompiler,metora/MesaGLSLCompiler,metora/MesaGLSLCompiler