In LLVM AOT/JIT compiler, only need to check the suspend_flags when memory is
a shared memory since the shared memory must be enabled for multi-threading,
so as not to impact the performance in non-multi-threading memory mode. Also
refine the LLVM IRs to check the suspend_flags.
And fix an issue of multi-tier jit for multi-threading, the instance of the child thread
should be removed from the instance list before it is de-instantiated.