RFR: 8272347: ObjectMethods::bootstrap should specify NPE if any argument except lookup is null

[Vicente Romero]

Please review this simple PR along with the associated CSR. The PR is basically adding a line the the specification of method `java.lang.runtime.ObjectMethods::bootstrap` stating under what conditions a NPE will be thrown.

TIA

link to the [CSR](https://bugs.openjdk.java.net/browse/JDK-8272852)

-------------

Commit messages:
 - 8272347: ObjectMethods::bootstrap should specify NPE if any argument except lookup is null

Changes: https://git.openjdk.java.net/jdk/pull/5226/files
 Webrev: https://webrevs.openjdk.java.net/?repo=jdk&pr=5226&range=00
  Issue: https://bugs.openjdk.java.net/browse/JDK-8272347
  Stats: 1 line in 1 file changed: 1 ins; 0 del; 0 mod
  Patch: https://git.openjdk.java.net/jdk/pull/5226.diff
  Fetch: git fetch https://git.openjdk.java.net/jdk pull/5226/head:pull/5226

PR: https://git.openjdk.java.net/jdk/pull/5226