SPU LLVM: Retry ARM64 TBL2 register scavenger failures

- Some SPU programs inexplicably fail to compile when TBL2/TBX2 are used.
- As an insane workaround, first try to compile with TBL2/TBX2, if LLVM crashes while compiling, try to compile the same program without TBL2/TBX2.

Utilities/Thread.cpp

@@ -3044,6 +3044,32 @@ void thread_ctrl::set_name(std::string name)
 	report_fatal_error(reason);
 }
 
+void thread_ctrl::silent_exit() noexcept
+{
+	if (const auto _this = g_tls_this_thread)
+	{
+		g_tls_error_callback();
+
+		u64 _self = _this->finalize(thread_state::errored);
+
+		if (_self == umax)
+		{
+			// Unused, detached thread support remnant
+			delete _this;
+		}
+
+		thread_base::finalize(umax);
+	}
+
+#ifdef _WIN32
+	_endthreadex(0);
+#else
+	pthread_exit(nullptr);
+#endif
+
+	std::abort();
+}
+
 void thread_ctrl::detect_cpu_layout()
 {
 	if (!g_native_core_layout.compare_and_swap_test(native_core_arrangement::undefined, native_core_arrangement::generic))