Darwin/aarch64: Fix "shadows declaration" warnings
Darwin/aarch64: Fix "shadows declaration" warnings

johne53/MB3Libffi,bgarrels/libffi,joshtriplett/libffi,s1341/libffi,Pan7/libffi,nmav/libffi,s1341/libffi,johne53/MB3Libffi,s1341/libffi,s1341/libffi,joshtriplett/libffi,bgarrels/libffi,rth7680/libffi,nmav/libffi,bgarrels/libffi,biosbits/libffi,plicease/libffi,johne53/MB3Libffi,bgarrels/libffi,rth7680/libffi,Distrotech/libffi,plicease/libffi,Pan7/libffi,Pan7/libffi,biosbits/libffi,joshtriplett/libffi,johne53/MB3Libffi,nmav/libffi,Distrotech/libffi,nmav/libffi,plicease/libffi,joshtriplett/libffi,rth7680/libffi,biosbits/libffi,plicease/libffi,Distrotech/libffi,biosbits/libffi,rth7680/libffi,johne53/MB3Libffi,Distrotech/libffi,Pan7/libffi