[perl6/specs] f538b1: default to P5 only when invoked as 'perl'

[GitHub]

  Branch: refs/heads/master
  Home:   https://github.com/perl6/specs
  Commit: f538b17f47340dea687b51477e6c9fe8b20dedee
      
https://github.com/perl6/specs/commit/f538b17f47340dea687b51477e6c9fe8b20dedee
  Author: Larry Wall <la...@wall.org>
  Date:   2012-03-02 (Fri, 02 Mar 2012)

  Changed paths:
    M S01-overview.pod

  Log Message:
  -----------
  default to P5 only when invoked as 'perl'