Add preprocessor support for parsing doubles.
Add double support to the flex stage.
Put in some of the basic double supported needed in the front end.
Add generic support for version numbers in the preprocessor, and the core, compatibility, and es profiles.
git-svn-id: https://cvs.khronos.org/svn/repos/ogl/trunk/ecosystem/public/sdk/tools/glslang@19949 e7fa87d3-cd2b-0410-9028-fcbf551c1848