When calling NullCheckedInvocation::invoke with a capture-less lambda,
GCC 9.3 determines that the expression
    std::declval<TheLambda>() != nullptr
is well-formed, and uses the version of invoke containing a nullptr
check. However, the compiler is also able to determine that this
expression can never be false, and emits a warning.

MIDI only plugins are no longer provided valid audio buffers
Graph nodes are only executed when they have active connections

Fix improper use of non-atomic pointer validity to report state of background search thread state

Following commit 093dbc7df1 pings of a
child process connection need to initialised explicitly. This commit
adds a missing initialisation.

Previously it was possible to have a dangling resource map. In that case
opening an AU from a file that did not have a resource map would lead to
using the previously unclosed map and attempting to load the previous
plugin again.

fc378aaf9a introduced a regression where
plugins with no audio channels (such as MIDI FX plugins) would receive
an audio buffer with a length-in-samples of '0', rather than the actual
block length.

These were mistakenly removed in afe5199848

With clang 13.0.0, and Apple clang version 13.1.6 (clang-1316.0.21.2),
the following code fails to compile with `-std=c++20 -O3 -msse3`:

    #include <immintrin.h>

    auto test (__m128 a)
    {
        return _mm_hadd_ps (_mm_hadd_ps (a, a), a);
    }

This partially reverts f43784dc: "macOS:  Propagate focus loss message when resigning key window status and only grab focus if window can become the key window"

The change introduced in 92f350e617 led to
a regression in the MoveEndpointByUnit function. In this case, a
backward movement by a single character *should* move the endpoint as
long as it remains within the text range.

The issue addressed by the faulty commit is better fixed by
special-casing the 'character' unit case in the ExpandToEnclosingUnit
function.

standalone apps

This change fixes a crash in Reaper when closing a plugin window
with ALT + F4.

Fixes an issue introduced in 72fa2d98e1
where zeromem might write past the end of the channel buffer.

eabcfbad26 incorrectly set the collection
behaviour NSWindowCollectionBehaviorFullScreenPrimary on all top-level
components, which would cause popup menus and callouts to appear in
their own space when launched from an app running in full-screen mode.

This fixes an issue where REAPER was unable to completely unload VST3
plugins.