RFR: 8320826: call allocate_shared_strings_array after all strings are interned

[Calvin Cheung]

On Tue, 28 Nov 2023 04:09:52 GMT, Ioi Lam <iklam at openjdk.org> wrote:

> `StringTable::allocate_shared_strings_array()` creates a Java object array that has the exact same size as the number of currently interned strings. Therefore, we need to move it to just before we enter the safepoint, where we know no more Java code would be execute.
> 
> I also had to change the assert in `StringTable::allocate_shared_strings_array()` to a condition check:  it's possible for `HeapShared::init_for_dumping()` to disable heap dumping when a Java agent transforms classes like jdk.internal.math.FDBigInteger.

LGTM

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Marked as reviewed by ccheung (Reviewer).

PR Review: https://git.openjdk.org/jdk/pull/16839#pullrequestreview-1753971340