trying to use this in a iOS 12.1 environment - getting an issue when I try and compile.

[jem5519]

getting -> Undefined symbols for architecture arm64: "_png_init_filter_functions_neon", referenced from: _png_init_filter_functions in pngrutil.o ld: symbol(s) not found for architecture arm64 clang: error: linker command failed with exit code 1 (use -v to see invocation)

seems to defined in pngpriv.h. -> line 140

Any suggestions are welcomed.