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

[Erik Joelsson]

On Wed, 13 Mar 2024 09:57:12 GMT, Magnus Ihse Bursie <ihse at openjdk.org> wrote:

> 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.
> 
> (This PR replaces https://github.com/openjdk/jdk/pull/18061 which got too messy.)

Marked as reviewed by erikj (Reviewer).

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PR Review: https://git.openjdk.org/jdk/pull/18267#pullrequestreview-1934201544