Use universal macro installation for both RPM 4 and RPM 5

%%install_macro has been added to the RPM package,
%%install_macro and %%_rpmacrodir will be added to RPM 5.

meson.spec

@@ -4,7 +4,7 @@
 Summary:	High productivity build system
 Name:		meson
 Version:	0.52.0
-Release:	1
+Release:	2
 License:	ASL 2.0
 Group:		Development/Tools
 Url:		http://mesonbuild.com
@@ -87,7 +87,7 @@ Valgrind, CCache and the like.
 %{_bindir}/%{name}
 %{_datadir}/polkit-1/actions/com.mesonbuild.install.policy
 %{_mandir}/man1/%{name}.1.*
-%{_sys_macros_dir}/%{name}.macros
+%{_rpmmacrodir}/*%{name}*
 %{py3_puresitedir}/%{name}-%{version}-py*.egg-info/
 %{py3_puresitedir}/mesonbuild/
 
@@ -105,7 +105,7 @@ Valgrind, CCache and the like.
 %py3_install
 
 # Install our rpm macro helper for meson
-install -D -m 0644 %{SOURCE2} %{buildroot}%{_sys_macros_dir}/%{name}.macros
+%install_macro meson %{SOURCE2}
 
 %if %{with check}
 %check