Tessellation partial implementation (not ready for use yet), including:

- the built-in constants
 - built-in variable declarations, some dependent on gl_MaxPatchVertices
 - layout qualifier for vertices (shared with geometry shader max_vertices)
 - layout qualifiers for vertex spacing, vertex order, point mode, and primitive type
 - link semantics for layout qualifiers

Still TBD:
 - patch qualifier and arrayed input handling
 - sizing of gl_out[]
 - additional semantic checking
 - supporting the extension on version 150

git-svn-id: https://cvs.khronos.org/svn/repos/ogl/trunk/ecosystem/public/sdk/tools/glslang@24468 e7fa87d3-cd2b-0410-9028-fcbf551c1848

Test/400.tesc

@@ -1,6 +1,35 @@
 #version 400 core
 
+layout(vertices = 4) out;
+int outa[gl_out.length()];
+
+layout(quads) in;                   // ERROR
+layout(ccw) out;                    // ERROR
+layout(fractional_even_spacing) in; // ERROR
+
+
 void main()
 {
     barrier();
+
+    int a = gl_MaxTessControlInputComponents +
+            gl_MaxTessControlOutputComponents +
+            gl_MaxTessControlTextureImageUnits +
+            gl_MaxTessControlUniformComponents +
+            gl_MaxTessControlTotalOutputComponents;
+
+    vec4 p = gl_in[1].gl_Position;
+    float ps = gl_in[1].gl_PointSize;
+    float cd = gl_in[1].gl_ClipDistance[2];
+
+    int pvi = gl_PatchVerticesIn;
+    int pid = gl_PrimitiveID;
+    int iid = gl_InvocationID;
+
+    gl_out[1].gl_Position = p;
+    gl_out[1].gl_PointSize = ps;
+    gl_out[1].gl_ClipDistance[1] = cd;
+
+    gl_TessLevelOuter[3] = 3.2;
+    gl_TessLevelInner[1] = 1.3;
 }