How can we test if the lex is adequate?

My guess would be to adopt one pkgsrc-wide definition of what adequate
means for lex (some SUS spec?), and have code that accepts the in-tree
lex except on known-to-have-broken-lex operating systems.  Not a test
per se, but a way to handle this in the future when pkgsrc runs on
even more places than it does now.  I think there is precedent for
this.

   Greg Troxel <gdt@ir.bbn.com>