At least MSVC sees a distinction between foo() and foo(void) and warns
about it.
extern int preprocess(void *ctx, const char **shader, char **info_log,
const struct gl_extensions *extensions, int api);
extern int preprocess(void *ctx, const char **shader, char **info_log,
const struct gl_extensions *extensions, int api);
-extern void _mesa_destroy_shader_compiler();
-extern void _mesa_destroy_shader_compiler_caches();
+extern void _mesa_destroy_shader_compiler(void);
+extern void _mesa_destroy_shader_compiler_caches(void);