Currently, it is not possible two make hotspot builds reproducible,
since the current date and time is always inserted using the special
macros __DATE__ and __TIME__. This patch makes it possible to override
these values from the build system, paving the way for making re-builds
of hotspot bit-by-bit identical.
On linux/gcc, we can now actually get bit-by-bit identical builds of
libjvm.so (if not using precompiled headers), so I've updated the
baseline-cmp profiles and compare script to reflect this.
Bug: https://bugs.openjdk.java.net/browse/JDK-8241271
WebRev:
http://cr.openjdk.java.net/~ihse/JDK-8241271-make-hotspot-reproducible/webrev.01
/Magnus
