mesa: allow xfb to be active in GLES when geometry shader is enabled.
mesa: allow xfb to be active in GLES when geometry shader is enabled.

OES_geometry_shader has wording to allow xfb when using Draw*Indirect
and DrawElements.

Signed-off-by: Ilia Mirkin <bcbbb7aa705ec3a5fc5824c01a845186c3d62fca@alum.mit.edu>
Reviewed-by: Anuj Phogat <e2026475996c48f0b97fd37e84129b3912980428@gmail.com>

metora/MesaGLSLCompiler,metora/MesaGLSLCompiler,metora/MesaGLSLCompiler