hos: change initialization API

This was needed to make stratosphere buildable with debugging on.

os:: assertions rely on GetCurrentThread() working, and this requires
the global os resource manager to be constructed. However, __appInit executes
before global constructors. We now require that hos::InitializeForStratosphere()
be called before anything else is done. This initializes the os resource manager,
sets the hos version for libnx, and may do more things in the future.

TODO: Consider replacing __appInit/__appExit with ams:: namespace functions in general,
and wrap them so that we guarantee hos::InitializeForStratosphere is called first, and
generally ensure a consistent stratosphere environment.

libraries/libstratosphere/source/os/impl/os_resource_manager.cpp

@@ -19,6 +19,6 @@
 namespace ams::os::impl {
 
     /* TODO: C++20 constinit */
-    OsResourceManager ResourceManagerHolder::s_resource_manager = {};
+    TYPED_STORAGE(OsResourceManager) ResourceManagerHolder::s_resource_manager_storage = {};
 
 }