Don't use deprecated dllwrap on Cygwin.

The preferred method is to use "cc -shared", and this allows binaries
to be rebased if required, unlike dllwrap.

Backpatch to 9.0 where we have buildfarm coverage.

There are still some issues with Cygwin, especially modern Cygwin, but
this helps us get closer to good support.

Marco Atzeri.

src/Makefile.shlib

@@ -309,6 +309,7 @@ ifeq ($(PORTNAME), unixware)
 endif
 
 ifeq ($(PORTNAME), cygwin)
+  LINK.shared		= $(CC) -shared
   ifdef SO_MAJOR_VERSION
     shlib		= cyg$(NAME)$(DLSUFFIX)
   endif
@@ -399,6 +400,16 @@ else # PORTNAME == cygwin || PORTNAME == win32
 
 # If SHLIB_EXPORTS is set, the rules below will build a .def file from
 # that.  Else we build a temporary one here.
+ifeq ($(PORTNAME), cygwin)
+$(shlib): $(OBJS) | $(SHLIB_PREREQS)
+	$(CC) $(CFLAGS)  -shared -o $@  $(OBJS) $(LDFLAGS) $(LDFLAGS_SL) $(SHLIB_LINK) $(LIBS) $(LDAP_LIBS_BE)
+
+$(stlib): $(OBJS) | $(SHLIB_PREREQS)
+	$(LINK.static) $@ $^
+	$(RANLIB) $@
+
+
+else
 ifeq (,$(SHLIB_EXPORTS))
 DLL_DEFFILE = lib$(NAME)dll.def
 exports_file = $(DLL_DEFFILE)
@@ -415,6 +426,7 @@ $(shlib): $(OBJS) $(DLL_DEFFILE) | $(SHLIB_PREREQS)
 $(stlib): $(shlib) $(DLL_DEFFILE) | $(SHLIB_PREREQS)
 	$(DLLTOOL) --dllname $(shlib) $(DLLTOOL_LIBFLAGS) --def $(DLL_DEFFILE) --output-lib $@
 
+endif # PORTNAME == cygwin 
 endif # PORTNAME == cygwin || PORTNAME == win32
 
 endif # enable_shared

src/makefiles/Makefile.cygwin

-# src/makefiles/Makefile.cygwin
 DLLTOOL= dlltool
-DLLWRAP= dllwrap
+# src/makefiles/Makefile.cygwin
 ifdef PGXS
 BE_DLLLIBS= -L$(libdir) -lpostgres
 else
@@ -40,6 +39,4 @@ endif
 
 # Rule for building a shared library from a single .o file
 %.dll: %.o
-	$(DLLTOOL) --export-all --output-def $*.def $<
-	$(DLLWRAP) -o $@ --def $*.def $< $(LDFLAGS) $(LDFLAGS_SL) $(BE_DLLLIBS)
-	rm -f $*.def
+	 $(CC) $(CFLAGS)  -shared -o $@ $<  $(LDFLAGS) $(LDFLAGS_SL) $(BE_DLLLIBS)