RFR: JDK-8245847 Update Profile.java to not require per-release updates

[Jonathan Gibbons]

Please review a small change to the implementation of Profile.java
so that it does not have to be updated on each release.

Although Profile.java theoretically permitted the use of profiles for
targets >= 8, they were effectively restricted by additional checks
elsewhere in java, in Arguments.java.

Long term, the expectation is that support for profiles will be deprecated
(JDK-8245246) and eventually removed (JDK-8245247.)

-- Jon

JBS: https://bugs.openjdk.java.net/browse/JDK-8245847
Webrev: http://cr.openjdk.java.net/~jjg/8245847/webrev.00/index.html