glslang: Formally track all built-in variables, right from the beginning, to enable avoiding all textual compares at any subsequent stage in the stack.  (To be used in future check ins.)


git-svn-id: https://cvs.khronos.org/svn/repos/ogl/trunk/ecosystem/public/sdk/tools/glslang@31224 e7fa87d3-cd2b-0410-9028-fcbf551c1848