meson: use -static-pie instead of -static in PIE mode

If compiling with -Db_pie=true, we should do PIE compilation (position
independent executables), even in the static mode.

The caveat is that people distributions actually override compilation
flags when doing their builds. They'll need to set the static flags
properly if they do such builds.

(cherry picked from commit 8b289a8c4d9e2f69a2c10d109c1c19f353005047)

src/core/meson.build

@@ -219,13 +219,24 @@ if conf.get('SYSTEMD_MULTICALL_BINARY') == 1
         ]
 endif
 
+if get_option('build-static')
+        if (get_option('b_pie') and
+            cc.links(basic_c_prog, args : '-static-pie', name : '-static-pie'))
+                systemd_link_args = ['-static-pie', '-Wl,-static,-pie']
+        else
+                systemd_link_args = ['-static']
+        endif
+else
+        systemd_link_args = []
+endif
+
 executables += [
         libexec_template + {
                 'name' : 'systemd',
                 'dbus' : true,
                 'public' : true,
                 'sources' : systemd_sources,
-                'link_args_static' : get_option('build-static') ? ['-static'] : [],
+                'link_args_static' : systemd_link_args,
                 'link_with' : [
                         libcore,
                         libshared,