In some recent ICU update, --enable-layoutex changed from defaulting to
the "same-as-layout" to "yes", so --disable-layout doesn't imply
--disable-layoutex anymore, but we removed the layoutex files.
Also fixes bug 926980 - load ICU data from an archive file.
Stop invoking ICU's autoconf build system. Instead, have hand-authored
moz.build files under config/external/icu to build what we need. In addition,
we'll commit a pre-built copy of the ICU data file (currently icudt56l.dat)
under config/external/icu/data to avoid having to build ICU host tools to
generate it. config/external/icu/data also contains some assembly files
which can generate an object file containing the ICU data file contents
so that the JS shell (or standalone JS builds) can be linked directly to
the data without having to deal with the external data file. This requires
yasm or GNU as.
Various bits of packaging have been updated to account for the ICU data file.
XPCOM initialization now sets the ICU data directory so ICU can locate its
data file.
The update-icu.sh script has been modified to read the list of C/C++ source
files out of the ICU Makefiles and update `sources.mozbuild` files under
config/external/icu, as well as build a local copy of ICU using its
autoconf build system to generate the ICU data file to be committed in-tree.
MozReview-Commit-ID: 8Pfkzqt6S1W
