lang/perl5.32: fix build on powerpc head

When building on powerpc (powerpc64 is fine) on head (which uses Clang), the following command causes a build crash when compiled with -O2:
LD_LIBRARY_PATH=/wrkdirs/usr/ports/lang/perl5.32/work/perl-5.32.0 ./miniperl -Ilib make_ext.pl lib/auto/DB_File/DB_File.so MAKE="/usr/bin/make" LIBPERL_A=libperl.so.5.32.0 LINKTYPE=dynamic

Compiling with -O1 is fine. Base GCC on stable/12 is fine, so only Clang needs this workaround.

PR: 248561
Approved by: mat (maintainer)