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

glslang/MachineIndependent/Versions.cpp

@@ -161,6 +161,7 @@ void TParseContext::initializeExtensionBehavior()
     extensionBehavior[GL_ARB_texture_gather]           = EBhDisable;
     extensionBehavior[GL_ARB_gpu_shader5]              = EBhDisablePartial;
     extensionBehavior[GL_ARB_separate_shader_objects]  = EBhDisable;
+    extensionBehavior[GL_ARB_tessellation_shader]      = EBhDisable;
 }
 
 // Get code that is not part of a shared symbol table, is specific to this shader,
@@ -183,6 +184,7 @@ const char* TParseContext::getPreamble()
             "#define GL_ARB_texture_gather 1\n"
             "#define GL_ARB_gpu_shader5 1\n"
             "#define GL_ARB_separate_shader_objects 1\n";
+            "#define GL_ARB_tessellation_shader 1\n";
     }
 }