Add support for call stack unwinding and function name resolution

Packages describing “unwind” as local USE flag

Package“unwind” Flag Description
dev-debug/ltraceUse sys-libs/libunwind for frame unwinding support
dev-debug/straceEnable stack backtraces (-k flag) via sys-libs/libunwind
dev-libs/eflEnable debug support via sys-libs/libunwind
dev-util/perfUse sys-libs/libunwind for frame unwinding support.
dev-util/sysprofUse sys-libs/libunwind to unwind the stack
media-libs/gstreamerEnable sys-libs/libunwind usage for better backtrace support in leaks tracer module
net-fs/sambaEnable libunwind usage for backtraces
www-apache/mod_backtraceUse sys-libs/libunwind to provide better resolution of function names.
x11-base/xorg-serverEnable libunwind usage for backtraces
x11-base/xwaylandEnable libunwind usage for backtraces

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