Make some changes to support out-of-the-box builds on FreeBSD:
- set cmake OpenGL type to `LEGACY`, the new `GLVND` type produces
unusable binaries on FreeBSD
- on FreeBSD add -I/usr/local/include to compiler flags, why this is
necessary I don't know
- look for llvm tools such as `llvm-ar` in `/usr/local/llvm-devel/bin`,
LTO works
- improve the `find_wx_util()` cmake function to handle `wx-config`
scripts named in the form e.g. `wxgtk3u-3.1-config`
- add FreeBSD support to `installdeps`
- make some minor changes to included headers based on macros such as
`__FreeBSD__` to compile on FreeBSD, including adding a `BSD.h` header
with some defines for e.g. `fseeko64`
- move the cmake X11 detection to before the wx compile tests, because
otherwise the extra compile flags for the wx tests make the X11 tests
fail
- make some minor changes to fix wx 2.8 compatibilty again, we don't
actually use 2.8 for FreeBSD but I was testing it
Signed-off-by: Rafael Kitover <rkitover@gmail.com>
2fedaa63a6