RFR: 8296440: Remove Method* handling from cleanup_inline_caches_impl [v3]

[Richard Reingruber]

> This PR replaces cleaning of static stubs in CompiledMethod::cleanup_inline_caches_impl() with a guarantee that it is actually not needed because the holder of the embedded target Method* is alive if the caller nmethod is not unloading.
> 
> The holder of the target Method* has to be alive because it is reachable from the caller nmethod's oop pool. This is checked by `check_path_to_callee()` when a statically bound call gets resolved.
> 
> C2i entry barriers can be removed for the same reason.
> 
> Testing:
> 
> Many rounds in our CI testing which includes most JCK and JTREG tests, Renaissance benchmark and SAP specific tests with fastdebug and release builds on the standard platforms plus PPC64.
> 
> I've also done tier1 and tier2 tests with -XX:-Inline and tier1 tests with ZGC.
> 
> I've started hotspot and jdk tier1 tests with -Xcomp. They were not finished when I stopped them after 24h.

Richard Reingruber has updated the pull request incrementally with one additional commit since the last revision:

  Feedback Coleene

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Changes:
  - all: https://git.openjdk.org/jdk/pull/12802/files
  - new: https://git.openjdk.org/jdk/pull/12802/files/876e55dc..2c2e49b5

Webrevs:
 - full: https://webrevs.openjdk.org/?repo=jdk&pr=12802&range=02
 - incr: https://webrevs.openjdk.org/?repo=jdk&pr=12802&range=01-02

  Stats: 60 lines in 4 files changed: 10 ins; 31 del; 19 mod
  Patch: https://git.openjdk.org/jdk/pull/12802.diff
  Fetch: git fetch https://git.openjdk.org/jdk.git pull/12802/head:pull/12802

PR: https://git.openjdk.org/jdk/pull/12802