[M3commit] [modula3/cm3] 954f39: add source path to error as was intended

[jaykrell]

  Branch: refs/heads/master
  Home:   https://github.com/modula3/cm3
  Commit: 954f3998555e184c001d4a54d1a492faa210167c
      https://github.com/modula3/cm3/commit/954f3998555e184c001d4a54d1a492faa210167c
  Author: jaykrell <jay.krell at cornell.edu>
  Date:   2015-08-13 (Thu, 13 Aug 2015)

  Changed paths:
    M m3-sys/cm3/src/Builder.m3

  Log Message:
  -----------
  add source path to error as was intended