Track which extensions were enabled or required, in the intermediate representation, for reflection of the consumer.

git-svn-id: https://cvs.khronos.org/svn/repos/ogl/trunk/ecosystem/public/sdk/tools/glslang@26155 e7fa87d3-cd2b-0410-9028-fcbf551c1848

Test/baseResults/dce.frag.out

@@ -1,6 +1,7 @@
 dce.frag
 Warning, version 400 is not yet complete; some version-specific features are present, but many are missing.
 
+Shader version: 400
 0:? Sequence
 0:5  Sequence
 0:5    move second child to first child (int)
@@ -139,4 +140,5 @@ Linked fragment stage:
 
 ERROR: Linking fragment stage: Missing entry point: Each stage requires one "void main()" entry point
 
+Shader version: 400