-g is required so the CI symbol upload has DWARF to send, but it was left in
the shipped binaries too: the Linux Release client is 563 MiB, 552 MiB of it
debug info, and every distribution channel pays for that.
Keep the build tree unchanged (CI uploads symbols from build/) and strip only
the packaged copy. A CPack pre-build script extracts each ELF's debug info to
COCKATRICE_DEBUG_SYMBOL_DIR and then runs `strip --strip-debug --strip-unneeded`.
.eh_frame is allocatable and survives, so unwinding is unaffected, and the build
ID is identical in the stripped binary and the sidecar.
Measured on a local Release build (GCC -O2 -g, WITH_CRASH_REPORTING=ON),
bytes:
binary build tree packaged before packaged after .debug sidecar
cockatrice 590,722,560 590,722,560 28,086,480 579,623,576
oracle 53,432,608 53,432,608 1,649,888 52,075,344
tar.gz of both trees: 289,964,521 -> 19,018,058 (~15x smaller).
Only ELF (Linux/BSD) is handled: Windows already links /DEBUG with separate
PDBs, and macOS extracts a dSYM from the bundle. Opt-out via
COCKATRICE_SPLIT_DEBUG_SYMBOLS; skipped with a warning when objcopy/strip are
missing. CPACK_PRE_BUILD_SCRIPTS (not CPACK_INSTALL_SCRIPTS, which runs before
staging) invokes it, and the script refuses to run unless CPACK_TEMPORARY_DIRECTORY
is a real CPack staging tree so a missing variable can never turn its glob into
a filesystem-wide walk.
