[master] RFR: Fix BasicLock to test for UseObjectMonitorTable rather than LM_LIGHTWEIGHT [v3]

[Coleen Phillimore]

On Wed, 19 Jun 2024 05:31:11 GMT, Axel Boldt-Christmas <aboldtch at openjdk.org> wrote:

>> Coleen Phillimore has updated the pull request incrementally with one additional commit since the last revision:
>> 
>>   And another place where we clear_object_monitor_cache if not using the OM table.
>
> src/hotspot/share/runtime/basicLock.inline.hpp line 38:
> 
>> 36:   assert(!UseObjectMonitorTable, "must be");
>> 37:   Atomic::store(&_metadata, header.value());
>> 38: }
> 
> These should stay exclusive to `LM_LEGACY`.

So I was unsure of this.  It's only LM_LEGACY that needs the displaced header?  Lightweight locking doesn't use it even with the table?

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PR Review Comment: https://git.openjdk.org/lilliput/pull/182#discussion_r1647484012