Move copydir.c from src/port to src/backend/storage/file

The previous commit to make copydir() interruptible prevented
postgres.exe from linking on MinGW and Cygwin, because on those
platforms libpgport_srv.a can't freely reference symbols defined
by the backend.  Since that code is already backend-specific anyway,
just move the whole file into the backend rather than adding further
kludges to deal with the symbols needed by CHECK_FOR_INTERRUPTS().

This probably needs some further cleanup, but this commit just moves
the file as-is, which should hopefully be enough to turn the
buildfarm green again.

src/backend/storage/file/Makefile

@@ -4,7 +4,7 @@
 #    Makefile for storage/file
 #
 # IDENTIFICATION
-#    $PostgreSQL: pgsql/src/backend/storage/file/Makefile,v 1.13 2008/02/19 10:30:08 petere Exp $
+#    $PostgreSQL: pgsql/src/backend/storage/file/Makefile,v 1.14 2010/07/02 17:03:30 rhaas Exp $
 #
 #-------------------------------------------------------------------------
 
@@ -12,6 +12,6 @@ subdir = src/backend/storage/file
 top_builddir = ../../../..
 include $(top_builddir)/src/Makefile.global
 
-OBJS = fd.o buffile.o
+OBJS = fd.o buffile.o copydir.o
 
 include $(top_srcdir)/src/backend/common.mk

src/port/copydir.c → src/backend/storage/file/copydir.c

@@ -11,7 +11,7 @@
  *	as a service.
  *
  * IDENTIFICATION
- *	  $PostgreSQL: pgsql/src/port/copydir.c,v 1.37 2010/07/01 20:12:40 rhaas Exp $
+ *	  $PostgreSQL: pgsql/src/backend/storage/file/copydir.c,v 1.1 2010/07/02 17:03:30 rhaas Exp $
  *
  *-------------------------------------------------------------------------
  */

src/port/Makefile

@@ -19,7 +19,7 @@
 # OBJS adds additional object files that are always compiled.
 #
 # IDENTIFICATION
-#    $PostgreSQL: pgsql/src/port/Makefile,v 1.38 2009/08/26 22:24:43 petere Exp $
+#    $PostgreSQL: pgsql/src/port/Makefile,v 1.39 2010/07/02 17:03:30 rhaas Exp $
 #
 #-------------------------------------------------------------------------
 
@@ -30,7 +30,7 @@ include $(top_builddir)/src/Makefile.global
 override CPPFLAGS := -I$(top_builddir)/src/port -DFRONTEND $(CPPFLAGS)
 LIBS += $(PTHREAD_LIBS)
 
-OBJS = $(LIBOBJS) chklocale.o copydir.o dirmod.o exec.o noblock.o path.o \
+OBJS = $(LIBOBJS) chklocale.o dirmod.o exec.o noblock.o path.o \
 	pgsleep.o pgstrcasecmp.o qsort.o qsort_arg.o sprompt.o thread.o
 ifneq (,$(filter $(PORTNAME),cygwin win32))
 OBJS += pipe.o