Implemented the <string.h> strerror() function.
Implemented the <string.h> strerror() function.

dryproject/libc11,dryc/libc11,ZakharBondia/libc11,dryc/libc11,ZakharBondia/libc11,dryproject/libc11,ZakharBondia/libc11,dryc/libc11,dryproject/libc11