glslang: Add API override of version and profile for testing purposes. From...

glslang: Add API override of version and profile for testing purposes.  From Lei Zhang <antiagainst@google.com>.

Add defaultProfile and forceDefaultVersionAndProfile into shader
compilation interface.

forceDefaultVersionAndProfile allows us to force parsing the input
shaders using defaultVersion and defaultProfile, regardless of
the #version directive in input shaders.

These two parameters enables us to programmatically invoke glslang
but specify version and profile from somewhere else like command
line.

git-svn-id: https://cvs.khronos.org/svn/repos/ogl/trunk/ecosystem/public/sdk/tools/glslang@31504 e7fa87d3-cd2b-0410-9028-fcbf551c1848