Problem extracting for lang/gcc13 on RHEL 8

["Morgan, Iain (ARC-TN)[InuTeq, LLC]" <iain.morgan%nasa.gov@localhost>]

Hello,

While working on a test build of a subset of packages from the 2023Q2 release on RHEL 8, I encountered a problem extracting one of the distfiles for lang/gcc13. The ISL tarball has changed from being compressed with bzip2 to xz, and the system-provided tar does not handle that.

===> Overriding tools for mpfr-4.2.0
===> Extracting for mpfr-4.2.0
===> Patching for mpfr-4.2.0
/bin/mv /tmp/pkgsrc.imorgan/2023Q2/lang/gcc13/work/gcc-13.1.0/mpfr-* /tmp/pkgsrc.imorgan/2023Q2/lang/gcc13/work/gcc-13.1.0/mpfr
/bin/tar -jxf /nobackup/imorgan/pkgsrc-rhel/distfiles/isl-0.24.tar.xz -C /tmp/pkgsrc.imorgan/2023Q2/lang/gcc13/work/gcc-13.1.0
bzip2: (stdin) is not a bzip2 file.
/bin/tar: Child returned status 2
/bin/tar: Error is not recoverable: exiting now

Setting TOOLS_PLATFORM.tar to nbtar did not fix the issue, but setting it to bsdtar did.  But, it would be good to handle this in a default pkgsrc install.

-- 
Iain