This means we can now construct a configure test for the library
presence. Previously these parameters were only figured out at
build time in plperl's GnuMakefile.
versions < 5.8. Also, if there's no Perl, emit a warning informing the
user that he won't be able to build from a CVS pull. This is exactly the
same treatment we give Bison and Perl, and for the same reasons.
perl_embed_ldflags setting. On OS X it seems that ExtUtils::Embed is
trying to force a universal binary to be built, but you need to specify
that a lot further upstream if you want Postgres built that way; the only
result of including -arch in perl_embed_ldflags is some warnings at the
plperl.so link step. Per my complaint and Jan Otto's suggestion.