Silence spurious maybe unused errors

These only show up during unity builds, and they originate from
Boost.Container's small vector. The compiler's diagnostic also doesn't
make any sense here so it's probably just a weird GCC thing.

src/common/serialization/vst3/event-list.h

@@ -24,6 +24,10 @@
 
 #pragma GCC diagnostic push
 #pragma GCC diagnostic ignored "-Wnon-virtual-dtor"
+// FIXME: When used in a Boost.Containers small vector, GCC somehow complains
+//        that the fields in `YaEvent` may be uninitialized (during the
+//        deserialization). This warning only shows up during a unity build.
+#pragma GCC diagnostic ignored "-Wmaybe-uninitialized"
 
 /**
  * A wrapper around `DataEvent` for serialization purposes, as this event

src/common/serialization/vst3/param-value-queue.h

@@ -24,6 +24,10 @@
 
 #pragma GCC diagnostic push
 #pragma GCC diagnostic ignored "-Wnon-virtual-dtor"
+// FIXME: When used in a Boost.Containers small vector, GCC somehow complains
+//        that the fields in this class may be uninitialized (during the
+//        deserialization). This warning only shows up during a unity build.
+#pragma GCC diagnostic ignored "-Wmaybe-uninitialized"
 
 /**
  * Wraps around `IParamValueQueue` for serializing a queue containing changes to