fixes with conditional defines in string.h
fixes with conditional defines in string.h

bradylee/nautilus_fs,yhx189/nautilus,bradylee/nautilus_fs,haiyang1992/NautilusVirtio,bradylee/nautilus_fs,yhx189/nautilus,haiyang1992/NautilusVirtio,yhx189/nautilus,haiyang1992/NautilusVirtio