Don't use ordinary NULL-terminated strings as Name datums.

Don't use ordinary NULL-terminated strings as Name datums.

Consumers are entitled to read the full 64 bytes pertaining to a Name;
using a shorter NULL-terminated string leads to reading beyond the end
its allocation; a SIGSEGV is possible.  Use the frequent idiom of
copying to a NameData on the stack.  New in 9.3, so no back-patch.