[DynInst_API:] [dyninst/dyninst] 6266e1: Make libiberty detection more flexible (#922)

[noreply@xxxxxxxxxx]

  Branch: refs/heads/master
  Home:   https://github.com/dyninst/dyninst
  Commit: 6266e1a9def4ee4157d3b0228380cfbb8095d669
      https://github.com/dyninst/dyninst/commit/6266e1a9def4ee4157d3b0228380cfbb8095d669
  Author: Tim Haines <thaines.astro@xxxxxxxxx>
  Date:   2020-11-23 (Mon, 23 Nov 2020)

  Changed paths:
    M cmake/Modules/FindLibIberty.cmake
    M common/src/symbolDemangle.c

  Log Message:
  -----------
  Make libiberty detection more flexible (#922)

Some platforms don't install libiberty in a subdirectory (e.g., /usr/include/libiberty), so account for that.