vala: add stubs for thread flag methods
As the Vala compiler does not define thread_flags() and
thread_link_flags(), depending on threads in any capacity will cause Meson to
fail.
Fixes
@@ -94,3 +94,9 @@ class ValaCompiler(Compiler):
return [vapi]
mlog.debug('Searched {!r} and {!r} wasn\'t found'.format(extra_dirs, libname))
return None
+
+ def thread_flags(self):
+ return []
+
+ def thread_link_flags(self):
+ return []
