link to libpng when building with wxW 3.3 on OSX

Author: 0tkl

tests/meson.build

@@ -57,6 +57,10 @@ elif host_machine.system() == 'darwin'
     tests_args += ['-DGTEST_HAS_POSIX_RE=0']
 endif
 
+if host_machine.system() == 'darwin' and get_option('wx_version').version_compare('>=3.3.0')
+    tests_deps += dependency('libpng')
+endif
+
 runner = executable(
     'gtest-main',
     tests_src,