RFR: 8263434: Dangling references after MethodComparator::methods_EMCP [v3]

[Aleksey Shipilev]

> SonarCloud reports the following problem in MethodComparator::methods_EMCP:
>  "Address of stack memory associated with local variable 's_new' is still referred to by the global variable '_s_new' upon returning to the caller. This will be a dangling reference"
> 
> Code inspection reveals the assignment to static variables is only needed to pass them to helper methods. So, while this is not a detectable bug (yet), it is still cleaner not to expose stack variables in globals.
> 
> Additional testing:
>  - [x] Linux x86_64 fastdebug `tier1`
>  - [x] Linux x86_64 fastdebug, `vmTestbase_nsk_jvmti`

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 five additional commits since the last revision:

 - Update copyrights
 - Drop excess parentheses
 - Merge branch 'master' into JDK-8263434-dangling-methodcomparator-ecmp
 - Sprinkling consts
 - 8263434: Dangling references after MethodComparator::methods_EMCP

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

Changes:
  - all: https://git.openjdk.java.net/jdk/pull/2937/files
  - new: https://git.openjdk.java.net/jdk/pull/2937/files/5acc4807..82bf43e0

Webrevs:
 - full: https://webrevs.openjdk.java.net/?repo=jdk&pr=2937&range=02
 - incr: https://webrevs.openjdk.java.net/?repo=jdk&pr=2937&range=01-02

  Stats: 33632 lines in 1544 files changed: 24507 ins; 4957 del; 4168 mod
  Patch: https://git.openjdk.java.net/jdk/pull/2937.diff
  Fetch: git fetch https://git.openjdk.java.net/jdk pull/2937/head:pull/2937

PR: https://git.openjdk.java.net/jdk/pull/2937