Implement copy-file on Windows

core/io/files/files.factor

@@ -97,7 +97,9 @@ TUPLE: no-parent-directory path ;
         ] }
     } cond drop ;
 
-: copy-file ( from to -- )
+HOOK: copy-file io-backend ( from to -- )
+
+M: object copy-file
     dup parent-directory make-directories
     <file-writer> [
         stdio get swap

extra/io/windows/windows.factor

@@ -116,6 +116,10 @@ M: windows-io delete-file ( path -- )
     normalize-pathname
     DeleteFile win32-error=0/f ;
 
+M: windows-io copy-file ( from to -- )
+    normalize-pathname
+    f CopyFile win32-error=0/f ;
+
 M: windows-io make-directory ( path -- )
     normalize-pathname
     f CreateDirectory win32-error=0/f ;