This contains a few hacks very specific to Qt's buildsystem. These can be
reverted once we split the build between native and target builds.
Qt's build contains a circular dependency when not using a system zlib.
By far the easiest fix is to switch to a system zlib, rather than Qt's own.
However, that confuses Qt's cross build which assumes that when using a system
zlib, it should also find a system (native) zlib for native tools. The build
breaks if that zlib is not present.
To solve this:
1. Always use a system zlib rather than the one provided by qt
2. Set force_bootstrap, which instructs the build tools to be built as though
we're cross-compiling (build != target)
3. For build tools, use qt's internal zlib so that a native zlib is not
required.
Step 3 means that if any zlib headers are found by the native build, it will
confuse Qt's internal zlib build. So we also need to make sure that the target
headers/libs aren't found. To do so, specify that our
cflags/cxxflags/cppflags/ldflags only apply for non-host builds.
# Conflicts:
# depends/patches/qt/mac-qmake.conf
qt5.7 changed the location of some of its symbols, creating a circular
dependency in Qt5Core. Rather than trying to fix that up, build our own zlib
rather than having it built for us.
Their buildsystem insists on using the installed ltranslate, but gets confused
about how to find it. Since we manually control the build order, just drop the
dependency.
Previously if we didn't have any local addresses, GetLocalAddress would return
0.0.0.0 and then we'd swap in a peer's notion of our address in AdvertiseLocal,
but then nServices would never get set.
Github-Pull: #10424
Rebased-From: 307013469f9a3b8f13d3eb9dbeea419a55148493
Defers to pre-defined version if found (e.g. protobuf). For protobuf case, the definitions are identical and thus include order should not affect results.
Github-Pull: #9366
Rebased-From: 815f4148b2eff6c64c764e910e79677d5a67adc7
