JDK7: Official change to Sun Studio 12 compilers on Solaris

This is the change request to make the SS12 compilers the official and default compiler to be used in jdk7.

This change should include:
  1. Makefile change to make SS12 the default compiler
  2. JPRT changes (make/jprt.* files) to make SS12 the default compiler. (top, jdk, and corba repositories)
  3. Updates to any README files that relate to compiler usage, top and jdk repository README files.
  4. Updates to any web pages for jdk7 to document use of SS12.
  5. Emails to openjdk aliases when this change happens.
  6. Changes to JPRT itself to make sure SS12 is the default on jdk7 builds.

Before this change is done, we need complete testing of a full jdk7 built with SS12, and performance runs with alacrity to verify that we accept and identify any regressions this change might create. Major problems in testing or performance could delay this official change, and accepting any regressions may need to be done by some official body, who knows?