Verilator 5.x from a source tarball on hosts with a minimal perl: FindBin and manpage failures

On a shared RHEL-family host, a Verilator 5.052 source build failed twice, both on host tooling and not the compiler. (1) A plain make -j builds bin/verilator_bin and verilator_bin_dbg, then stops at make: *** [Makefile:206: verilator_gantt.1] Error 127, because the manpage target needs a POD-to-man tool the host lacks. make -C src builds just the binaries and skips the docs. (2) The bin/verilator wrapper is a Perl script that does use FindBin qw($RealBin $RealScript), and some minimal perl installs ship without FindBin (Can't locate FindBin.pm in @INC). Without root, put a ~10-line FindBin.pm that sets $Bin/$Script/$RealBin/$RealScript from File::Spec->rel2abs($0) and Cwd::realpath into a private dir and export PERL5LIB to it. Getopt::Long, IO::File, Pod::Usage and Cwd were present there; check each with perl -MModule -e1 before assuming only FindBin is missing. Run verilator --version only after PERL5LIB is set, or the wrapper dies before your build script reaches the design.