Move DEFFILE to EXTDLDFLAGS

So that it is no longer needed in ruby.pc.in.

configure.ac

@@ -3751,7 +3751,7 @@ AS_CASE(["$target_os"],
 		LIBRUBY_DLDFLAGS="${LIBRUBY_DLDFLAGS}"' $(RUBYDEF)'
 	    ])
 	    EXPORT_PREFIX=' '
-	    DLDFLAGS="${DLDFLAGS}"' $(DEFFILE)'
+	    EXTDLDFLAGS='$(DEFFILE)'
 	    AC_LIBOBJ([win32/win32])
 	    AC_LIBOBJ([win32/file])
 	    COMMON_LIBS=m

template/ruby.pc.in

@@ -49,7 +49,6 @@ LIBRUBYARG_STATIC=@LIBRUBYARG_STATIC@
 LIBRUBYARG=@LIBRUBYARG@
 LIBS=@LIBS@
 DLDFLAGS=@DLDFLAGS@
-DEFFILE=@DEFFILE@
 
 Name: Ruby
 Description: Object Oriented Script Language