context: only declare arbfp cache for GL

We were trying to declare and initializing an arbfp program cache for
GLES but since the prototypes for the _hash and _equal functions were
only available for GL this broke the GLES builds. By #ifdefing the code
to conditionally declare/initialize for GL only this should hopefully
fix GLES builds.

cogl/cogl-context.c

@@ -208,8 +208,10 @@ cogl_create_context (void)
 
   _context->legacy_depth_test_enabled = FALSE;
 
+#ifdef HAVE_COGL_GL
   _context->arbfp_cache = g_hash_table_new (_cogl_pipeline_arbfp_hash,
                                             _cogl_pipeline_arbfp_equal);
+#endif
 
   for (i = 0; i < COGL_BUFFER_BIND_TARGET_COUNT; i++)
     _context->current_buffer[i] = NULL;
@@ -360,7 +362,9 @@ _cogl_destroy_context (void)
   g_slist_free (_context->texture_types);
   g_slist_free (_context->buffer_types);
 
+#ifdef HAVE_COGL_GL
   g_hash_table_unref (_context->arbfp_cache);
+#endif
 
   g_free (_context);
 }

cogl/cogl-context.h

@@ -91,7 +91,9 @@ typedef struct
 
   int               legacy_state_set;
 
+#ifdef HAVE_COGL_GL
   GHashTable       *arbfp_cache;
+#endif
 
   /* Textures */
   CoglHandle        default_gl_texture_2d_tex;