RFR: 8255441: Cleanup ciEnv/jvmciEnv::lookup_method-s [v2]

[Aleksey Shipilev]

> Static analysis complains there is a potentially uninitialized `dest_method` after the switch, oblivious of `ShouldNotReachHere()`. This can be cleaned up along with related code.

Aleksey Shipilev has updated the pull request with a new target base due to a merge or a rebase. The incremental webrev excludes the unrelated changes brought in by the merge/rebase. The pull request contains three additional commits since the last revision:

 - Merge branch 'master' into JDK-8255441-cleanup-linkresolver
 - Use `fatal` with proper message
 - 8255441: Cleanup ciEnv/jvmciEnv::lookup_method-s

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Changes:
  - all: https://git.openjdk.java.net/jdk/pull/875/files
  - new: https://git.openjdk.java.net/jdk/pull/875/files/b9fe313c..fb800b60

Webrevs:
 - full: https://webrevs.openjdk.java.net/?repo=jdk&pr=875&range=01
 - incr: https://webrevs.openjdk.java.net/?repo=jdk&pr=875&range=00-01

  Stats: 1878 lines in 74 files changed: 1371 ins; 310 del; 197 mod
  Patch: https://git.openjdk.java.net/jdk/pull/875.diff
  Fetch: git fetch https://git.openjdk.java.net/jdk pull/875/head:pull/875

PR: https://git.openjdk.java.net/jdk/pull/875