Add support for call stack unwinding and function name resolution

Packages describing “unwind” as local USE flag

Package “unwind” Flag Description
www-apache/mod_backtrace Use sys-libs/libunwind to provide better resolution of function names.
dev-util/sysprof Use sys-libs/libunwind to unwind the stack
x11-base/xwayland Enable libunwind usage for backtraces
media-libs/gstreamer Enable sys-libs/libunwind usage for better backtrace support in leaks tracer module
dev-util/strace Enable stack backtraces (-k flag) via sys-libs/libunwind
dev-util/perf Use sys-libs/libunwind for frame unwinding support.
x11-base/xorg-server Enable libunwind usage for backtraces
net-fs/samba Enable libunwind usage for backtraces
dev-libs/efl Enable debug support via sys-libs/libunwind
dev-util/ltrace Use sys-libs/libunwind for frame unwinding support

All packages providing a “unwind” USE flag (22)