Currently, CFLAGS and CXXFLAGS are not making it into the compile line.
This is because meson appends CFLAGS/CXXFLAGS from the environment only
for native but not for cross builds (probably to keep cross-builds more
isolated). As a result, we need to make sure these vars goes into
meson.cross. This is similar to what cmake.bbclass does with
OECMAKE_C_FLAGS and OECMAKE_CXX_FLAGS.
Change c_args and cpp_args in meson.cross to include these vars, and
update write_config[vardeps] accordingly.
Signed-off-by: Martin Kelly <mkelly@xevo.com> Signed-off-by: Ross Burton <ross.burton@intel.com>
