Fix meson uuid header check so it works with MSVC

The OSSP uuid.h file includes unistd.h, so to use it with MSVC we need to
include the postgres include directories so it picks up our version of
that in src/include/port/win32_msvc. Adjust the meson test accordingly.

meson.build

@@ -1353,7 +1353,10 @@ if uuidopt != 'none'
     error('unknown uuid build option value: @0@'.format(uuidopt))
   endif
 
-  if not cc.has_header_symbol(uuidheader, uuidfunc, args: test_c_args, dependencies: uuid)
+  if not cc.has_header_symbol(uuidheader, uuidfunc,
+                              args: test_c_args,
+                              include_directories: postgres_inc,
+                              dependencies: uuid)
     error('uuid library @0@ missing required function @1@'.format(uuidopt, uuidfunc))
   endif
   cdata.set('HAVE_@0@'.format(uuidheader.underscorify().to_upper()), 1)