RFR: 8263591: Two C2 compiler phases with the name "after matching" [v3]

[Tobias Hartmann]

> [JDK-8223347](https://bugs.openjdk.java.net/browse/JDK-8223347) added a `PHASE_AFTER_MATCHING` which is equivalent to  `PHASE_MATCHING` but only printed at level 3 and before node verification: 
> https://github.com/openjdk/jdk/blob/20297a1bebfe03c45344a713ec561c97888c4750/src/hotspot/share/opto/compile.cpp#L2757-L2769
> 
> I don't think there is any benefit in having both and therefore removed it together with some other dead code (`idx` is always `0`).
> 
> Thanks,
> Tobias

Tobias Hartmann has updated the pull request incrementally with one additional commit since the last revision:

  Removed PHASE_AFTER_MATCHING from enum

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

Changes:
  - all: https://git.openjdk.java.net/jdk/pull/3026/files
  - new: https://git.openjdk.java.net/jdk/pull/3026/files/1b887fb5..df8cb7a0

Webrevs:
 - full: https://webrevs.openjdk.java.net/?repo=jdk&pr=3026&range=02
 - incr: https://webrevs.openjdk.java.net/?repo=jdk&pr=3026&range=01-02

  Stats: 1 line in 1 file changed: 0 ins; 1 del; 0 mod
  Patch: https://git.openjdk.java.net/jdk/pull/3026.diff
  Fetch: git fetch https://git.openjdk.java.net/jdk pull/3026/head:pull/3026

PR: https://git.openjdk.java.net/jdk/pull/3026