mesa/*: use an internal enum for tessellation primitive types.

To avoid dragging gl.h into places it has no business being,
defined tessellation primitive mode to an enum.

This has a lot of fallout all over the place.

Reviewed-by: Kenneth Graunke <kenneth@whitecape.org>
Part-of: <https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/14605>

src/compiler/shader_enums.h

@@ -994,6 +994,14 @@ enum gl_tess_spacing
    TESS_SPACING_FRACTIONAL_EVEN,
 };
 
+enum tess_primitive_mode
+{
+   TESS_PRIMITIVE_UNSPECIFIED,
+   TESS_PRIMITIVE_TRIANGLES,
+   TESS_PRIMITIVE_QUADS,
+   TESS_PRIMITIVE_ISOLINES,
+};
+
 /**
  * A compare function enum for use in compiler lowering passes.  This is in
  * the same order as GL's compare functions (shifted down by GL_NEVER), and is