Fix MSVC build.

When I moved pg_crc.c from src/port to src/common, I forgot to modify MSVC
build script accordingly.

src/tools/msvc/Mkvcbuild.pm

@@ -68,7 +68,7 @@ sub mkvcbuild
 	  chklocale.c crypt.c fls.c fseeko.c getrusage.c inet_aton.c random.c
 	  srandom.c getaddrinfo.c gettimeofday.c inet_net_ntop.c kill.c open.c
 	  erand48.c snprintf.c strlcat.c strlcpy.c dirmod.c noblock.c path.c
-	  pgcheckdir.c pg_crc.c pgmkdirp.c pgsleep.c pgstrcasecmp.c pqsignal.c
+	  pgcheckdir.c pgmkdirp.c pgsleep.c pgstrcasecmp.c pqsignal.c
 	  mkdtemp.c qsort.c qsort_arg.c quotes.c system.c
 	  sprompt.c tar.c thread.c getopt.c getopt_long.c dirent.c
 	  win32env.c win32error.c win32setlocale.c);
@@ -76,7 +76,7 @@ sub mkvcbuild
 	push(@pgportfiles, 'rint.c') if ($vsVersion < '12.00');
 
 	our @pgcommonallfiles = qw(
-	  exec.c pg_lzcompress.c pgfnames.c psprintf.c relpath.c rmtree.c
+	  exec.c pg_crc.c pg_lzcompress.c pgfnames.c psprintf.c relpath.c rmtree.c
 	  string.c username.c wait_error.c);
 
 	our @pgcommonfrontendfiles = (@pgcommonallfiles, qw(fe_memutils.c));