[mono] Fix the race condition issue of aot_module loading

[fanyang-mono]

Fixes #103782

[lambdageek]

This isn't 100% correct (if the current thread is holding the loader lock, while another thread is trying to load some assemblies while loading hte AOT module, the other thread won't make progress). But it should handle 80% of the cases (where we just had a simple race, rather than a potential deadlock).

We decided this is ok.

The correct solution would be to make load_aot_module safe to call from multiple threads at the same time using a lock-free "create and publish" strategy. But that will be a much harder rewrite because load_aot_module has global effects (on the JIT info tables, for example)

[lambdageek]

Need to also set the module to AOT_MODULE_NOT_FOUND here:

runtime/src/mono/mono/mini/aot-runtime.c

Lines 2086 to 2096 in c5e8f83

	if (!sofile) {
	// Maybe do these on more platforms ?
	#ifndef HOST_WASM
	if (mono_aot_only && !mono_use_interpreter && table_info_get_rows (&assembly->image->tables [MONO_TABLE_METHOD])) {
	aot_name = g_strdup_printf ("%s%s", assembly->image->name, MONO_SOLIB_EXT);
	g_error ("Failed to load AOT module '%s' ('%s') in aot-only mode.\n", aot_name, assembly->image->name);
	g_free (aot_name);
	}
	#endif
	return;
	}

[fanyang-mono]

/azp run runtime-ioslike

[azure-pipelines]

Azure Pipelines successfully started running 1 pipeline(s).

[fanyang-mono]

/azp run runtime-android

[azure-pipelines]

Azure Pipelines successfully started running 1 pipeline(s).

[fanyang-mono]

/azp run runtime-android

[fanyang-mono]

/azp run runtime-ioslike

[azure-pipelines]

Azure Pipelines successfully started running 1 pipeline(s).

[azure-pipelines]

Azure Pipelines successfully started running 1 pipeline(s).

[steveisok]

The android and ios/tvos failures are known. LGTM!

[gabriel-kozma]

Is this issue going to be merged back on .net 8.0? I'm having an issue when IL stripping assemblies on Android

[fanyang-mono]

@gabriel-kozma Yes, I've opened an PR to backport this fix to .NET8. However, this fix is on track to be shipped as part of .NET9 Preview7 as well.