RFR: 8310494: Do not include constantPool.hpp from instanceKlass.hpp [v3]

[Ioi Lam]

> instanceKlass.hpp is needed quite frequently for HotSpot C++ sources, but constantPool.hpp is much less frequently.
> 
> This PR is the first step of reducing the inclusion of constantPool.hpp, by removing it from instanceKlass.hpp
> 
> I moved a bunch of inline functions into instanceKlass.cpp. These don't seem to be performance related.

Ioi Lam 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 four additional commits since the last revision:

 - Merge branch 'master' into 8310494-remove-constantPool-from-instanceKlass-hpp
 - moved comment about on_stack() to the cpp file (which already has the comment)
 - @stefank review comments
 - 8310494: Do not include constantPool.hpp from instanceKlass.hpp

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

Changes:
  - all: https://git.openjdk.org/jdk/pull/14597/files
  - new: https://git.openjdk.org/jdk/pull/14597/files/68697195..f8bd76ac

Webrevs:
 - full: https://webrevs.openjdk.org/?repo=jdk&pr=14597&range=02
 - incr: https://webrevs.openjdk.org/?repo=jdk&pr=14597&range=01-02

  Stats: 2078 lines in 190 files changed: 1087 ins; 325 del; 666 mod
  Patch: https://git.openjdk.org/jdk/pull/14597.diff
  Fetch: git fetch https://git.openjdk.org/jdk.git pull/14597/head:pull/14597

PR: https://git.openjdk.org/jdk/pull/14597