RFR: 8252898: remove bulk registration of JFR CompilerPhaseType names [v2]

[Doug Simon]

> The changes made in [JDK-8193210](https://bugs.openjdk.java.net/browse/JDK-8193210) support only [bulk
> registration](https://github.com/openjdk/jdk/blob/4e6a4af1866d0007d368b78bf78b6a8e1c8be425/src/hotspot/share/compiler/compilerEvent.hpp#L75)
> of compiler phase names with JFR. However, Graal only registers compiler phase names upon first execution of the phase
> since the set of phases is not known during VM initialization. This means registration of a Graal phase name needs to
> do unnecessary work, wrapping a single name into an array to conform to the bulk registration API. This pull request
> updates the registration API to be in terms of a registering a single phase name.

Doug Simon has refreshed the contents of this pull request, and previous commits have been removed. The incremental
views will show differences compared to the previous content of the PR. The pull request contains one new commit since
the last revision:

  8252898: remove bulk registration of JFR CompilerPhaseType names

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Changes:
  - all: https://git.openjdk.java.net/jdk/pull/77/files
  - new: https://git.openjdk.java.net/jdk/pull/77/files/662f9854..740c5894

Webrevs:
 - full: https://webrevs.openjdk.java.net/?repo=jdk&pr=77&range=01
 - incr: https://webrevs.openjdk.java.net/?repo=jdk&pr=77&range=00-01

  Stats: 3 lines in 2 files changed: 0 ins; 2 del; 1 mod
  Patch: https://git.openjdk.java.net/jdk/pull/77.diff
  Fetch: git fetch https://git.openjdk.java.net/jdk pull/77/head:pull/77

PR: https://git.openjdk.java.net/jdk/pull/77