gawk: update to 5.4.0

gawk: update to 5.4.0

Changes from 5.3.x to 5.4.0:
 * Use Mike Haertel's MinRX regular expression matcher by default.
   The old regex and dfa engines are still available.
 * New @nsinclude directive: like @include but doesn't reset
   the namespace to "awk".
 * lshift()/rshift() return 0 when shifting more bits than in uintmax_t.
 * Persistent memory: store meta-info in backing file; warn on
   version mismatch; allow dynamic extensions with persistent memory.
 * ordchr extension now supports multibyte / wide characters.
 * length(array) is no longer an extension (POSIX 2024); --posix
   no longer rejects it and --lint no longer warns.
 * --traditional rationalised to match BWK awk behaviour.
 * Assertions are now enabled in the C code.
 * Hexadecimal floating-point values may now be used in source,
   strtonum() and -n/--non-decimal-data option.
 * UDP networking support is now deprecated, will be removed in 6.0.
 * Reading regular disk input files is somewhat faster (no timeout check).
 * Various bug fixes.

Link: https://git.savannah.gnu.org/cgit/gawk.git/plain/NEWS?h=gawk-5.4.0
Signed-off-by: Daniel Golle <redacted>