Add geometry-shader stream, invocations, max_vertices, lines, triangles, etc. layout qualifiers, and their default/inheritance behaviors, and some other misc. geometry shader features. (Geometry shaders are not yet done though.)

git-svn-id: https://cvs.khronos.org/svn/repos/ogl/trunk/ecosystem/public/sdk/tools/glslang@23679 e7fa87d3-cd2b-0410-9028-fcbf551c1848

Test/400.geom

@@ -9,3 +9,6 @@ void main()
 
     int id = gl_InvocationID;
 }
+
+layout(invocations = 3) out outbn { int a; }; // ERROR, not on a block
+layout(max_vertices = 127, invocations = 4) out;