RFR: 8327045: Consolidate -fvisibility=hidden as a basic flag for all compilation [v3]

[Magnus Ihse Bursie]

> After we removed mapfiles, we can setup -fvisibility=hidden (and -Wl,--exclude-libs,ALL) in the most basic flags, so this applies to all compilation.
> 
> This will remove duplicate code and make the underlying assumptions of the build clearer.
> 
> Doing this will result in the same output result -- with one exception: native test libraries has not been compiled with this flag (and this caused an error for a Oracle-internal test).

Magnus Ihse Bursie 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 visibility-hidden-everywhere
 - 8327045: Consolidate -fvisibility=hidden as a basic flag for all compilation
 - Update line number for dereference_null  in TestDwarf
 - 8327460: Compile tests with the same visibility rules as product code

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

Changes:
  - all: https://git.openjdk.org/jdk/pull/18061/files
  - new: https://git.openjdk.org/jdk/pull/18061/files/350fcb5d..e481408a

Webrevs:
 - full: https://webrevs.openjdk.org/?repo=jdk&pr=18061&range=02
 - incr: https://webrevs.openjdk.org/?repo=jdk&pr=18061&range=01-02

  Stats: 17611 lines in 323 files changed: 9397 ins; 7067 del; 1147 mod
  Patch: https://git.openjdk.org/jdk/pull/18061.diff
  Fetch: git fetch https://git.openjdk.org/jdk.git pull/18061/head:pull/18061

PR: https://git.openjdk.org/jdk/pull/18061