Make File Changes For CR4239752

[Dan Xu]

Hi,

I have a bug fix which needs make file changes, which can be reviewed at 
http://cr.openjdk.java.net/~dxu/4239752/webrev/.

With the above make file changes, I am able to build jdk successfully in 
old build system. But if I built it using new build system, the build 
process failed and complained about missing generated header file, 
java_io_FileSystem.h.

I wonder how I can make the equivalent make file changes in the new 
build-infra Makefiles. Thanks!

-Dan