Added property structure copy functions.
Added property structure copy functions.



ngrewe/libobjc2,gnustep/libobjc2,darlinghq/darling-libobjc2,crystax/android-vendor-libobjc2,davidchisnall/libobjc2,gnustep/libobjc2,darlinghq/darling-libobjc2,crystax/android-vendor-libobjc2,ngrewe/libobjc2,davidchisnall/libobjc2