Implement GL_MAX_PROGRAM_TEXEL_OFFSET and GL_MAX_TEXTURE_LOD_BIAS

Implement GL_MAX_PROGRAM_TEXEL_OFFSET and GL_MAX_TEXTURE_LOD_BIAS

- GL_MAX_PROGRAM_TEXEL_OFFSET and GL_MIN_PROGRAM_TEXEL_OFFSET were
  technically already properly implemented, since the spec mentions
  that the behavior outside of these limits is undefined, and
  SwiftShader has no actual hard limit for these parameters.
- GL_MAX_TEXTURE_LOD_BIAS also has no hard limit in SwiftShader,
  other than the limit imposed on LOD itself, so that limit was
  used for GL_MAX_TEXTURE_LOD_BIAS.

Change-Id: I60b15b7f7a0febbc3e6582caff6c6a414a5d4964
Reviewed-on: https://swiftshader-review.googlesource.com/11709
Reviewed-by: Nicolas Capens <nicolascapens@google.com>
Tested-by: Alexis Hétu <sugoi@google.com>