gcc and ld support enabling "garbage collection" of unused input sections.
This can be used to eliminate unused coding from native libraries (especially when already compiling the objects with compiler flags -ffunction-sections -fdata-sections .
See for details the --gc-sections and --print-gc-sections parts of the ld documentation :

https://linux.die.net/man/1/ld

The change will enable link-time section-gc for linux , except linux s390x which has been enabled already with JDK-8234525 ..