* codegen-units, lto, opt-level - Set to values to optimize binary
size[1].
* overflow-checks - Enabled because in release mode, integer overflows
are defined as two's complement wrap[2]. It is highly unlikely that
any program is intentionally relying on this behaviour; it would be
better to panic instead of continue execution in this case.
* debug, debug-assertions, panic, rpath - Set to their default (release)
values, to override any settings made by packages, e.g. ripgrep sets
debug = 1[3].