Fix defined for static compile.
Fix defined for static compile.

See https://bugs.php.net/bug.php?id=63086

bd808/pecl-file_formats-yaml,bd808/pecl-file_formats-yaml,php/pecl-file_formats-yaml,php/pecl-file_formats-yaml,Danack/PeclYaml,bd808/pecl-file_formats-yaml,Sean-Der/pecl-file_formats-yaml,Danack/PeclYaml,Sean-Der/pecl-file_formats-yaml,bd808/pecl-file_formats-yaml,php/pecl-file_formats-yaml,Danack/PeclYaml,Sean-Der/pecl-file_formats-yaml,php/pecl-file_formats-yaml