This patch contains three fixes.
1) As in Bug 1515982, we use the constant for RT_MANIFEST instead of
the define, which needs winuser.rh to be included
2) We stop exempting the mingw builds from RCINCLUDE in
toolkit/library/moz.build which causes us to miss all of the
resources in xul.dll
3) We explicitly include IA2Marshal.dll instead of relying on
compiler magic to include it for us.
Differential Revision: https://phabricator.services.mozilla.com/D26295
--HG--
extra : moz-landing-system : lando