jdk8 makefile changes

[Kelly O'Hair]

Heads up...

We expect to do a sync up of the jdk8/build forest with the latest in the build-infra forest in the next few days.

As the new build-infra project starts getting more solid and we contemplate when we can switch
the default to building with the new build-infra Makefiles (we don't know exactly when yet).

                **** IMPORTANT NOTICE ****
It will be important that *anyone* making *any* changes to the jdk8 Makefiles keep the build-dev
or build-infra mailing lists informed.
For a period of time we need to maintain two separate build mechanisms, and we want to make sure
that both build the same thing.
The hotspot repository is the one exception where we don't have two sets of makefiles, but we still
would like to know when anyone is changing the makefiles or anything to do with the build process.
              *****************************

We will soon be running both builds and doing comparisons of the resulting j2sdk-image files from
both to insure we match. So if we detect differences we will be tracking down how those differences
happened (that's a hint that we will be watching :^).

More information on the new build-infra Makefiles can be found at:
   http://openjdk.java.net/projects/build-infra/

User Guide is at:
  http://openjdk.java.net/projects/build-infra/guide.html

Some preliminary timings for building the product image (effectively, build/j2sdk-image/):
   					OLD			NEW build-infra times      (All estimates, similar VMs/Zones)
 linux_i586                	(21m 59s)		(08m 13s)
 linux_x64                  	(13m 34s)		(07m 04s)
 solaris_i586                	(26m 14s)		(11m 31s)
 solaris_sparc              	(54m 02s)		(28m 21s)
 windows_i586            	(55m 49s)		(32m 22s)  (old used MKS, build-infra only uses CYGWIN)
 windows_x64            	(36m 36s)		(23m 50s)      "        "     "

Notes:
  * Machines with more processors will reduce the build time for build-infra builds, less so with the old Makefiles.
  * Always use local disk or /tmp (all above timings use /tmp, always local disk)
  * Above uses VMs for Windows and Linux, raw hardware would be faster
  * Use of ccache can sometimes speed things up, but can also skew the timings,
      in the above measurements OLD used ccache, NEW did not.

-kto