Cleanup: GCC redundant declarations

Previous waning suppression was only tested with clang.

intern/clog/CLG_log.h

@@ -148,7 +148,6 @@ void CLG_logref_init(CLG_LogRef *clg_ref);
 /** Declare outside function, declare as extern in header. */
 #define CLG_LOGREF_DECLARE_GLOBAL(var, id) \
 	static CLG_LogRef _static_ ## var = {id}; \
-	extern CLG_LogRef *var; \
 	CLG_LogRef *var = &_static_ ## var
 
 /** Initialize struct once. */

source/blender/draw/engines/eevee/eevee_materials.c

@@ -103,8 +103,6 @@ extern char datatoc_volumetric_lib_glsl[];
 
 extern char datatoc_gpu_shader_uniform_color_frag_glsl[];
 
-extern Material defmaterial;
-
 /* *********** FUNCTIONS *********** */
 
 #if 0 /* Used only to generate the LUT values */

source/blender/editors/space_node/drawnode.c

@@ -2963,9 +2963,6 @@ void ED_node_init_butfuncs(void)
 	/* Fallback types for undefined tree, nodes, sockets
 	 * Defined in blenkernel, but not registered in type hashes.
 	 */
-	/*extern bNodeTreeType NodeTreeTypeUndefined;*/
-	extern bNodeType NodeTypeUndefined;
-	extern bNodeSocketType NodeSocketTypeUndefined;
 
 	/* default ui functions */
 	NodeTypeUndefined.draw_nodetype = node_draw_default;

source/blender/python/intern/bpy.h

@@ -28,4 +28,7 @@ extern PyObject *bpy_package_py;
 void BPY_atexit_register(void);
 void BPY_atexit_unregister(void);
 
+extern struct CLG_LogRef *BPY_LOG_CONTEXT;
+extern struct CLG_LogRef *BPY_LOG_RNA;
+
 #endif  /* __BPY_H__ */