st/mesa: avoid exposing EXT_texture_integer for pre-GLSL 1.30

For drivers building up to GL(ES)3, only expose the actual extension if
the API will let it be used (e.g. via overrides/debug flags that enable
higher versions).

Signed-off-by: Ilia Mirkin <imirkin@alum.mit.edu>
freedreno: pass number of instances to draw

Signed-off-by: Ilia Mirkin <imirkin@alum.mit.edu>
gallium: support instanced rendering in u_primconvert

Signed-off-by: Ilia Mirkin <imirkin@alum.mit.edu>
freedreno/a3xx: add support for vertexid and instanceid sysvals

Signed-off-by: Ilia Mirkin <imirkin@alum.mit.edu>
WIP freedreno/ir3: add POPC/BREV/MSB/LSB opcode support

These are part of GLES3.1 and ARB_gpu_shader5. The bitfield
extract/insert operations are still to be done.

XXX this apparently doesn't work... maybe the opcodes aren't really
there?

Signed-off-by: Ilia Mirkin <imirkin@alum.mit.edu>
WIP freedreno/ir3: add TG4 support

Signed-off-by: Ilia Mirkin <imirkin@alum.mit.edu>
WIP srgb rb