Add GJS macros

These are useful for Gnome's Javascript applications.

https://bugzilla.gnome.org/show_bug.cgi?id=766460

Makefile.am

@@ -6,6 +6,8 @@ dist_aclocal_DATA = \
 	autoconf-archive/m4/ax_append_link_flags.m4			\
 	autoconf-archive/m4/ax_append_flag.m4				\
 	autoconf-archive/m4/ax_check_compile_flag.m4			\
+	autoconf-archive/m4/ax_check_girs_gjs.m4			\
+	autoconf-archive/m4/ax_check_gir_symbols_gjs.m4			\
 	autoconf-archive/m4/ax_check_link_flag.m4			\
 	autoconf-archive/m4/ax_is_release.m4				\
 	autoconf-archive/m4/ax_code_coverage.m4				\
@@ -16,6 +18,7 @@ dist_aclocal_DATA = \
 	autoconf-archive/m4/ax_compiler_flags_gir.m4			\
 	autoconf-archive/m4/ax_cxx_compile_stdcxx_11.m4			\
 	autoconf-archive/m4/ax_pkg_check_modules.m4			\
+	autoconf-archive/m4/ax_prog_gjs.m4				\
 	autoconf-archive/m4/ax_require_defined.m4			\
 	$(NULL)
 

autoconf-archive @ be2a3e99

-Subproject commit b87ebf8630e85447adc29fe26ab2e4a2d82877f9
+Subproject commit be2a3e994be81101dd0e02da57200cc9fae84b0a