gcc 4.6 backports required by 38

[GoogleCodeExporter]

This is not an insuperable requirement, but 39+ will likely be.

Need to fix for 4.6:

https://bugzilla.mozilla.org/show_bug.cgi?id=1134511 (disable -pedantic-errors 
by undoing it in 
https://bug1128413.bugzilla.mozilla.org/attachment.cgi?id=8560920)

https://bugzilla.mozilla.org/show_bug.cgi?id=1134487

https://bugzilla.mozilla.org/show_bug.cgi?id=1136040 (as suggested in 
https://bugzilla.mozilla.org/show_bug.cgi?id=1102195)

This seems to be sufficient for 4.6 on 38.

For 39+ I guess we'll need 4.8.

Original issue reported on code.google.com by classi...@floodgap.com on 22 Mar 2015 at 4:15

[GoogleCodeExporter]

See also: https://bugzilla.mozilla.org/show_bug.cgi?id=1145631

Original comment by classi...@floodgap.com on 22 Mar 2015 at 4:17