i965/fs: Don't drop force_writemask_all and _sechalf when copying a CSE temporary.
i965/fs: Don't drop force_writemask_all and _sechalf when copying a CSE temporary.

LOAD_PAYLOAD instructions need the same treatment as any other
generator instructions, at least FB writes and typed surface messages
will need a payload built with non-zero execution controls.

Reviewed-by: Matt Turner <789b315743a28dd066a4ba1459c35951c291d8a6@gmail.com>

metora/MesaGLSLCompiler,metora/MesaGLSLCompiler,metora/MesaGLSLCompiler