bug #525522 is back in firefox 37.0.1 (probably 37 too, but that wasn't in portage).
if test "x$LG_PAGE" == "xdetect"; then
on line 6569 of the generated configure.
Can be fixed the same way as in the last bug.
+ 06 Apr 2015; Ian Stakenvicius (_AxS_) <email@example.com> firefox-37.0.1.ebuild,
+ firefox-37 works now that jit is forced-on, removing mask