Proposed resolution:

This wording is relative to N4981.

1. Modify [cstring.syn] as indicated:

   -3- The functions memcpy and memmove are signal-safe ([support.signal]). Both Each of these functions implicitly create creates objects ([intro.object]) in the destination region of storage immediately prior to copying the sequence of characters to the destination. Each of these functions returns a pointer to a suitable created object, if any, otherwise the value of the first parameter.