gallium: add new opcodes for ARB_gs5 bit manipulation support

Signed-off-by: Ilia Mirkin <imirkin@alum.mit.edu>
glsl: fix bitfield_insert use when doing ldexp lowering

bitfield_insert expects glsl_type::int_type arguments, not uint vectors

Signed-off-by: Ilia Mirkin <imirkin@alum.mit.edu>
mesa/st: implement new bit manipulation opcodes

Also pipe through [IU]MUL_HI and lower ldexp. This provides coverage of
all new ARB_gpu_shader5 functions except uaddCarry/usubBorrow and
interpolateAt*.

Signed-off-by: Ilia Mirkin <imirkin@alum.mit.edu>
softpipe: add tgsi_exec support for new bit manipulation opcodes

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