This includes
- doing prescan of shader to know version/profile before parsing it
- putting precision qualifiers on built-in ES symbols
- getting most built-in state correct for core/compatibility/missing profile
- adding gl_VertexID and gl_InstanceID, among other ES 300 built-in symbols
- adding the ES 300 gl_Max/Min constants
- accepting shaders that contain nothing but whitespace without generating an error
git-svn-id: https://cvs.khronos.org/svn/repos/ogl/trunk/ecosystem/public/sdk/tools/glslang@20627 e7fa87d3-cd2b-0410-9028-fcbf551c1848