Some tools like automake set PERL5LIB in their build, so we make the change here to prepend to the existing envar value.
Issue from automake:
Can't locate [strict.pm](http://strict.pm/) in @INC (you may need to install the strict module) (@INC entries checked: /jenkins/PortBuild/automake/automake-1.16.5/lib/ /jenkins/PortBuild/automake/automake-1.16.5/lib/ ../lib/site_perl/5.38.0/os390 ../lib/site_perl/5.38.0 ../lib/5.38.0/os390 ../lib/5.38.0) at ./doc/help2man line 25.
Some tools like automake set PERL5LIB in their build, so we make the change here to prepend to the existing envar value.
Issue from automake: