During build, we create a touch file which is literally named '_the..'.
While cygwin handles this without issues, Windows believes this to be a
file with the extension "." and can't touch it, that is, not delete or
move it.
This patch renames this file (and others created at the same time) to
have a proper extension (".marker"), which Windows deals with properly.
Bug: https://bugs.openjdk.java.net/browse/JDK-8007897
WebRev:
http://cr.openjdk.java.net/~ihse/JDK-8007897-make-file-has-illegal-name-in-window/webrev.01
/Magnus
