glsl: Implement ARB_texture_query_lod

v2 [mattst88]:
   - Rebase.
   - #define GL_ARB_texture_query_lod to 1.
   - Remove comma after ir_lod in ir.h for MSVC.
   - Handled ir_lod in ir_hv_accept.cpp, ir_rvalue_visitor.cpp,
     opt_tree_grafting.cpp.
   - Rename textureQueryLOD to textureQueryLod, see
     https://www.khronos.org/bugzilla/show_bug.cgi?id=821
   - Fix ir_reader of (lod ...).
v3 [mattst88]:
   - Rename textureQueryLod to textureQueryLOD, pending resolution of
     Khronos 821.
   - Add ir_lod case to ir_to_mesa.cpp.

Reviewed-by: Matt Turner <mattst88@gmail.com>
Reviewed-by: Kenneth Graunke <kenneth@whitecape.org>

src/glsl/glcpp/glcpp-parse.y

@@ -1233,6 +1233,9 @@ glcpp_parser_create (const struct gl_extensions *extensions, int api)
 
 	      if (extensions->ARB_texture_multisample)
 	         add_builtin_define(parser, "GL_ARB_texture_multisample", 1);
+
+	      if (extensions->ARB_texture_query_lod)
+	         add_builtin_define(parser, "GL_ARB_texture_query_lod", 1);
 	   }
 	}