This is in preparation to enforcing this sorting during make check.
The script only checks for alphabetical sorting, which leads to unexpected
sorting between classes sharing a common prefix (eg the correct order is:
gvir_config_domain_get_foo;
gvir_config_domain_interface_set_foo;
gvir_config_domain_set_foo;

instead of

gvir_config_domain_get_foo;
gvir_config_domain_set_foo;
gvir_config_domain_interface_set_foo;

if we want to keep methods from the same class grouped in the symbol file.