gawk: disable persistent memory allocator due to licensing

In gawk-5.2, a feature that allows gawk to preserve memory between runs:
   https://www.gnu.org/software/gawk/manual/html_node/Persistent-Memory.html
was added. The files that implement this, support/pma.[ch], are licensed
under the AGPL3 which some entities perfer to avoid. Force people to knowingly
opt into using this feature and license using:
   PACKAGECONFIG:append:pn-gawk = " pma-if-64bit"
where pma is an abbreviation for persistent memory allocator and the
"-if-64bit" suffix is a indicator to users that the feature only works
for 64 bit targets. Also add AGPL to LICENSE and LICENSE:${PN}, when using pma.

Correct the license to be AGPL-3.0-or-later. There hasn't been a change in
the license terms, at least for main.c, haven't changed significantly in
the last 15 years:

License-Update: Reflects conditional AGPL use and more as described above.

Testing requires a non-root account and following the example in the link above:
  $ truncate -s <size> data.pma
  $ chmod 0600 data.pma
  $ GAWK_PERSIST_FILE=data.pma gawk 'BEGIN { print ++i }'
  1
  $ GAWK_PERSIST_FILE=data.pma gawk 'BEGIN { print ++i }'
  2
  $ GAWK_PERSIST_FILE=data.pma gawk 'BEGIN { print ++i }'
  3

This works on qemu[x86-|arm|riscv]64 but not on qemu[arm|x86] where the
--enable-pma is ignored because there is a requirement and build-time test
for 8 byte void pointers in m4/pma.m4:
  if test "$SKIP_PERSIST_MALLOC" = no && test $ac_cv_sizeof_void_p -eq 8

Finally, remove an old comment about GPLv2, GPLv3 versions of gawk
since this is no longer important as the GPLv2 version is not maintained.

(From OE-Core rev: d7b6887dfbe2817ceb03d44a59210f65bbb25390)

Signed-off-by: Randy MacLeod <Randy.MacLeod@windriver.com>
Signed-off-by: Mathieu Dubois-Briand <mathieu.dubois-briand@bootlin.com>
Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>

meta/recipes-extended/gawk/gawk_5.3.2.bb

@@ -6,14 +6,21 @@ HOMEPAGE = "https://www.gnu.org/software/gawk/"
 BUGTRACKER  = "bug-gawk@gnu.org"
 SECTION = "console/utils"
 
-# gawk <= 3.1.5: GPL-2.0-only
-# gawk >= 3.1.6: GPL-3.0-only
-LICENSE = "GPL-3.0-only"
-LIC_FILES_CHKSUM = "file://COPYING;md5=d32239bcb673463ab874e80d47fae504"
+LICENSE = "GPL-3.0-or-later & AGPL-3.0-or-later"
+LIC_FILES_CHKSUM = "file://COPYING;md5=d32239bcb673463ab874e80d47fae504 \
+                    file://support/pma.c;md5=bb0026ee5e8b950e67d670dd2d60cc93;beginline=8;endline=19 \
+                    file://support/pma.h;md5=bb0026ee5e8b950e67d670dd2d60cc93;beginline=8;endline=19"
+
+LICENSE:${PN} = "GPL-3.0-or-later"
+LICENSE:${PN}:append = " ${@bb.utils.contains('PACKAGECONFIG', 'pma-if-64bit', ' & AGPL-3.0-or-later', '', d)}"
 
 PACKAGECONFIG ??= "readline mpfr"
 PACKAGECONFIG[readline] = "--with-readline,--without-readline,readline"
 PACKAGECONFIG[mpfr] = "--with-mpfr,--without-mpfr, mpfr"
+# pma: persistent memory allocator:
+# Disabled by default due to AGPL license.
+# Note that PMA works only for 64-bit targets and is automatically disabled at configure time otherwise.
+PACKAGECONFIG[pma-if-64bit] = "--enable-pma,--disable-pma, "
 
 SRC_URI = "${GNU_MIRROR}/gawk/gawk-${PV}.tar.gz \
            file://run-ptest \