Description of problem:

Since gcc6 landed in Fedora we are unable to build firefox/thunderbird/xulrunner on aarch64.

Version-Release number of selected component (if applicable):

firefox-45.0.1-2.fc24 http://arm.koji.fedoraproject.org/koji/buildinfo?buildID=363311
thunderbird-38.6.0-6.fc24 http://arm.koji.fedoraproject.org/koji/buildinfo?buildID=355038
xulrunner-44.0-5.fc24 http://arm.koji.fedoraproject.org/koji/buildinfo?buildID=359583

How reproducible:

always

Steps to Reproduce:
1. do build of firefox/thunderbird/xulrunner on aarch64

Actual results:

Executing /builddir/build/BUILD/thunderbird-38.6.0/comm-esr38/objdir/dist/bin/xpcshell -g /builddir/build/BUILD/thunderbird-38.6.0/comm-esr38/objdir/dist/bin/ -a /builddir/build/BUILD/thunderbird-38.6.0/comm-esr38/objdir/dist/bin/ -f /builddir/build/BUILD/thunderbird-38.6.0/comm-esr38/mozilla/toolkit/mozapps/installer/precompile_cache.js -e precompile_startupcache("resource://gre/");
Traceback (most recent call last):
  File "/builddir/build/BUILD/thunderbird-38.6.0/comm-esr38/mozilla/toolkit/mozapps/installer/packager.py", line 403, in <module>
    main()
  File "/builddir/build/BUILD/thunderbird-38.6.0/comm-esr38/mozilla/toolkit/mozapps/installer/packager.py", line 397, in main
    args.source, gre_path, base)
  File "/builddir/build/BUILD/thunderbird-38.6.0/comm-esr38/mozilla/toolkit/mozapps/installer/packager.py", line 156, in precompile_cache
    errors.fatal('Error while running startup cache precompilation')
  File "/builddir/build/BUILD/thunderbird-38.6.0/comm-esr38/mozilla/python/mozbuild/mozpack/errors.py", line 101, in fatal
    self._handle(self.FATAL, msg)
  File "/builddir/build/BUILD/thunderbird-38.6.0/comm-esr38/mozilla/python/mozbuild/mozpack/errors.py", line 96, in _handle
    raise ErrorMessage(msg)
mozpack.errors.ErrorMessage: Error: Error while running startup cache precompilation
/builddir/build/BUILD/thunderbird-38.6.0/comm-esr38/mozilla/toolkit/mozapps/installer/packager.mk:36: recipe for target 'stage-package' failed
make[1]: Leaving directory '/builddir/build/BUILD/thunderbird-38.6.0/comm-esr38/objdir/mail/installer'
/builddir/build/BUILD/thunderbird-38.6.0/comm-esr38/mozilla/../mail/build.mk:19: recipe for target 'install' failed
make[1]: *** [stage-package] Error 1
make: *** [install] Error 2


Expected results:

package builds

Additional info: