Ever since bug 969164, the js build system, when building gecko (not when
building standalone) uses a autoconf-js.mk file for its config.
One of the suboptimal ways we have to retrigger builds when the build
configuration changes (changes to e.g. configure.in can do that) is to
make most things depend on autoconf.mk. Which unfortunately doesn't
account for the fact the js/src subdirectory uses a different file.
In practice, this means that some classes of changes to the js build
system, not accompanied with toplevel build system changes may no
trigger the corresponding rebuilds in the js subtree on incremental
builds.
Before, we would run configure in both top-level and js/src, and both
configures would traverse their own set of moz.builds, without actual
knowledge about the other. With this change, both configures still run,
but only top-level traverses moz.build files, and uses js/src's
config.status when traversing its moz.build files. This allows a better
sharing of information between both build systems and the removal of many
hacks.
This also moves running libffi and icu configure to top-level.
Standalone js builds still have their own configure doing moz.build traversal,
as before.
--HG--
rename : config/autoconf.mk.in => config/autoconf-js.mk.in
rename : config/emptyvars.mk.in => config/emptyvars-js.mk.in
