Patch to enable ccache to work most of the time.

[Kelly O'Hair]

I can be a reviewer. Looks good.

And I appreciate the makefile comment :^)

I think this also explains some strange behaviors with pre-compiled headers.
If the version number definition gets into the pre-compiled header file, it becomes invalid with any
version string change and can cause build failures, or at least on windows it has.

-kto

On Jan 23, 2012, at 9:05 AM, Fredrik Öhrström wrote:

> Simple fix to prevent the version define to be passed to all Hotspot c++ files.
> 
> Since the version define contains a time and date (when the build nr is not set),the ccache can only be used for 1 minute after the build....
> 
> This fix makes sure that only vm_version.o depends on the version number. Thus all the other files can be ccached efficiently.
> 
> http://cr.openjdk.java.net/~ohrstrom/webrev-2012-01-23-prep-for-ccache/
> 
> Jim, can you make me an author on HSX?
> 
> Robert, can you sponsor me?
> 
> //Fredrik
>