RFR: 8290075: [JVMCI] only blessed methods can link against EventWriterFactory.getEventWriter [v3]

[Doug Simon]

> [JDK-8282420](https://bugs.openjdk.org/browse/JDK-8282420) introduced the notion of "blessed methods" which are those that can link against `jdk.jfr.internal.event.EventWriterFactory.getEventWriter(long)`.
> This PR enhances the JVMCI ConstantPool API so that it can take a caller context when resolving a method to enforce this constraint properly.

Doug Simon has updated the pull request with a new target base due to a merge or a rebase. The pull request now contains three commits:

 - Merge remote-tracking branch 'openjdk-jdk/master' into JDK-8290075
 - moved JVMCI code to end of file
 - support special linkage rules for jdk.jfr.internal.event.EventWriterFactory.getEventWriter(long) in JVMCI

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

Changes: https://git.openjdk.org/jdk/pull/9449/files
 Webrev: https://webrevs.openjdk.org/?repo=jdk&pr=9449&range=02
  Stats: 146 lines in 12 files changed: 127 ins; 6 del; 13 mod
  Patch: https://git.openjdk.org/jdk/pull/9449.diff
  Fetch: git fetch https://git.openjdk.org/jdk pull/9449/head:pull/9449

PR: https://git.openjdk.org/jdk/pull/9449