bt2: disable some warnings for native_bt.c

Replicate the changes done in the master branch by building native_bt.c
with the -Wno-unused-parameter and -Wno-missing-field-initializers
options.

Those changes were lifted from commits dd420a9 and ecd7492.

Signed-off-by: Jérémie Galarneau <jeremie.galarneau@efficios.com>
Change-Id: I5e1f57f47f5bf81ef395707cccafaf0c15f9f8a1
Reviewed-on: https://review.lttng.org/c/babeltrace/+/12192
Tested-by: jenkins <jenkins@lttng.org>

src/bindings/python/bt2/Makefile.am

@@ -128,6 +128,10 @@ WARN_CFLAGS += -Wno-redundant-decls
 # `__cplusplus` is not defined.
 WARN_CFLAGS += -Wno-undef
 
+# For SWIG generated code
+WARN_CFLAGS += -Wno-missing-field-initializers
+WARN_CFLAGS += -Wno-unused-parameter
+
 BUILD_FLAGS=CC="$(CC)" \
 		CFLAGS="$(GLIB_CFLAGS) $(AM_CFLAGS) $(CFLAGS) $(WARN_CFLAGS)" \
 		CPPFLAGS="$(AM_CPPFLAGS) $(CPPFLAGS) -I$(srcdir)/bt2" \