Request for review: 7022370 Launcher ergonomics doesn't need per-architecture implementations

[David Holmes]

Hopefully all interested parties are addressed in the cc lists.

webrev at:

http://cr.openjdk.java.net/~dholmes/7022370/webrev/

The launcher ergonomics (ergo.c) currently relies on per-architecture, 
eg ergo_sparc.c, ergo_i586.c, files to define the actual ergonomics 
operations. Only x86 is actually CPU specific, both sparc and zero share 
the same platform independent implementation. It will simplify things if 
we provide a platform independent default in ergo.c that is 
conditionally compiled, and modify the build system to cause that 
compilation if a platform specific ergo file is not found.

We can potentially delete all the ergo_*.c files except for ergo_i586.c, 
and we no longer require that there be a per-architecture file, which 
makes additional porting easier.

Gary: do you mind seeing ergo_zero.c go away, or would you prefer to 
leave it in case someone is doing a local customization? I suppose the 
some consideration could be given to ergo_sparc.c too. Is anybody aware 
of downstream distros that modify these files to change the default 
ergonomics policies?

Thanks,
David Holmes