The dead_strip linker option on macOS removes functions and data that are unreachable by the entry point or exported symbols.
Setting it can reduce the size of some binaries we generate quite a lot, for example (product build, Xcode 15 is used) :
(before -> after setting the option)
1.4M -> 1.1M images/jdk/lib/libfontmanager.dylib
264K -> 248K images/jdk/lib/libjavajpeg.dylib
152K -> 132K images/jdk/lib/libjli.dylib
388K -> 296K images/jdk/lib/liblcms.dylib
164K -> 128K images/jdk/lib/libzip.dylib

and libjvm :
20M -> 18M images/jdk/lib/server/libjvm.dylib
146M -> 137M images/jdk/lib/server/libjvm.dylib.dSYM

Because libjvm contains 'dead' code that would be stripped, but is not really 'dead' but used in some scenarios (debuggers, serviceability agent), we limit the dead_strip linker option to jdk native libs.