Reject GLSL ES 3.00 shaders for OpenGL ES 2.0 contexts.
Reject GLSL ES 3.00 shaders for OpenGL ES 2.0 contexts.

Bug 19331817

Change-Id: I72128c6b3cb672d4b74578086814fde2c2c6db99
Reviewed-on: https://swiftshader-review.googlesource.com/2292
Reviewed-by: Nicolas Capens <0612353e1fcebbfd4b302d9337447ca0cdfa9122@google.com>
Tested-by: Nicolas Capens <0612353e1fcebbfd4b302d9337447ca0cdfa9122@google.com>

bkaradzic/SwiftShader,bkaradzic/SwiftShader,google/swiftshader,google/swiftshader,google/swiftshader,bkaradzic/SwiftShader,bkaradzic/SwiftShader,bkaradzic/SwiftShader