SL-19690: Follow up on Rye Mutt's fix for shutdown crashes.

SL-19644: De-virtualize pushBatch

Rather than continuing to propagate try/catch (Closed)
(aka LLThreadSafeQueueInterrupt) constructs through the code base, make
WorkQueueBase::post() return bool indicating success (i.e. ! isClosed()).
This obviates postIfOpen(), which no one was using anyway.

In effect, postIfOpen() is renamed post(), bypassing the exception when
isClosed().

Review existing try/catch blocks of that sort, changing to test for post()
returning false.

Fix exceptions during shutdown causing early program termination

Fix LLThreadSafeQueueInterrupt in WorkQueueBase::postTo during shutdown by catching and returning false

Bump still uses its own pushBumpBatch function - OK, works the same as
before.

enable github actions mac nightly builds

DRTVWR-559: Replace debugLoggingEnabled() function with LL_DEBUGS().

Newer C++ compilers have different semantics around LLSDArray's special copy
constructor, which was essential to proper LLSD nesting. In short, we can no
longer trust LLSDArray to behave correctly. Now that we have variadic
functions, get rid of LLSDArray and replace every reference with llsd::array().

Fix SL-19675 crash due to thread unsafe LLRefCount usage possibly related to SL-19648

Cleanup with SL-19675 fix.  lifted empty check outside the workqueue post and cleaned up indentation

It seems newer compilers have a different interpretation of exactly when to
engage LLSDArray's copy constructor. In particular, this assignment:

some_LLSD_map[key] = LLSDArray(...)(...)...;

used to convert the LLSDArray object directly to LLSD; now it first calls the
custom copy constructor, which embeds the intended array within an outer array
before assigning it into the containing map.

The newer llsd::array() function avoids that problem because what it returns
is already an LLSD object.

Taking inventory of LLSDArray assignments of that form turned up a number of
workarounds like LLSD(LLSDArray(...)). Replacing those with llsd::array() is
both simpler and more readable.

Tip of the hat to Chorazinallen for surfacing this issue!

(cherry picked from commit bb718155)

Delete the debugLoggingEnabled() (changed to LL_DEBUGS()) stanzas deleted by
the upstream.

The trouble with debugLoggingEnabled() is that it locked mutexes and searched
maps every time that call was reached. LL_DEBUGS() has the same functionality
(albeit with idiosyncratic syntax) but performs expensive lookups only once
per session, caching the result in a local static variable.

DRTVWR-559 Optimization pass, make it so profileAvatar can read back GPU timer without a frame stall.