On other platforms, RUBY_SO_NAME is defined from RUBY_API_VERSION.
ruby_version contains the ABI version, which is not needed.
RUBY_API_VERSION is defined as MAJOR.MINOR.
Related issues
Bug #18667: Windows mswin RbConfig::CONFIG['LIBRUBY_SO'], ABI version '+' suffix
Added by peterzhu2118 (Peter Zhu) over 3 years ago
[Bug #18667] Define RUBY_API_VERSION on Windows
On other platforms, RUBY_SO_NAME is defined from RUBY_API_VERSION.
ruby_version contains the ABI version, which is not needed.
RUBY_API_VERSION is defined as MAJOR.MINOR.