glsl: Record in gl_shader whether the shader uses GLSL ES.

glsl: Record in gl_shader whether the shader uses GLSL ES.

Previously we recorded just the GLSL version, with the knowledge that
100 means GLSL 1.00 ES.  With the advent of GLSL 3.00 ES, this is
going to get more complex, and eventually will probably become
ambiguous (GLSL 4.00 already exists, and GLSL 4.00 ES is likely to be
created some day).

To reduce confusion, this patch simply records whether the shader is
GLSL ES as an explicit boolean.

[v2, idr]: s/IsEs(Shader|Prog)/IsES/  Suggested by Ken and Eric.

Reviewed-by: Ian Romanick <ian.d.romanick@intel.com> [v1]
Reviewed-by: Kenneth Graunke <kenneth@whitecape.org>
Reviewed-by: Eric Anholt <eric@anholt.net>
Acked-by: Carl Worth <cworth@cworth.org>