BUG #15280: Clang 6.0.1 compiler warning - strlcpy

The following bug has been logged on the website:

Bug reference: 15280
Logged by: Steven Winfield
Email address: steven(dot)winfield(at)cantabcapital(dot)com
PostgreSQL version: 11beta2
Operating system: RHEL 7.4
Description:

Hi,

While compiling 11beta2 using clang 6.0.1 this warning crops up quite a lot
in an otherwise quiet build process - so I thought it might be of
interest:

pg_rewind.c:724:4: warning: implicitly declaring library function 'strlcpy'
with type 'unsigned long (char *, const char *, unsigned long)'
[-Wimplicit-function-declaration]
strlcpy(full_path, progname, sizeof(full_path));
^
pg_rewind.c:724:4: note: include the header <string.h> or explicitly provide
a declaration for 'strlcpy'
1 warning generated.

In my pg_config.h I have:
#define HAVE_DECL_STRLCPY 1

...and HAVE_STRLCPY is left undefined:
/* #undef HAVE_STRLCPY */

Best wishes,
Steven.