[NativeAOT-LLVM] Implement inlined thread statics for the single-threaded mode

[SingleAccretion]

Today we use the general (and slow) path for thread statics. We can do better since in principle thread statics should have the same cost as regular statics in threadless WASM.

Tasks:

1. Implement "inlined" thread statics support in ILC targeting single-threaded WASM.
2. Implement inlined access in the Jit.

Ideally, the Jit implementation should still produce threadness-agnostic bitcode as it does today, but that can be compromised on if needed.