The link-editor provides string table compression, that can result in reduced .dynstr and .strtab sections. This default processing can be disabled using the link-editor's -z nocompstrtab option. See String Table Compression.
The -z ignore option has been extended to eliminate unreferenced sections during a link-edit. See Remove Unused Material.
Unreferenced dependencies can be determined using ldd(1). See the -U option.
Greater flexibility in defining a symbols visibility is provided with the protected mapfile directive. See SYMBOL_SCOPE / SYMBOL_VERSION Directives.