user: Declare get_task_state() once in 'accel/tcg/vcpu-state.h'

While each user emulation implentation defines its own
TaskState structure, both use the same get_task_state()
declaration, in particular in common code (such gdbstub).
Declare the method once in "accel/tcg/vcpu-state.h".

Signed-off-by: Philippe Mathieu-Daudé <philmd@linaro.org>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Message-Id: <20240428221450.26460-10-philmd@linaro.org>
diff --git a/accel/tcg/vcpu-state.h b/accel/tcg/vcpu-state.h
new file mode 100644
index 0000000..e407d91
--- /dev/null
+++ b/accel/tcg/vcpu-state.h
@@ -0,0 +1,18 @@
+/*
+ * SPDX-FileContributor: Philippe Mathieu-Daudé <philmd@linaro.org>
+ * SPDX-FileCopyrightText: 2023 Linaro Ltd.
+ * SPDX-License-Identifier: GPL-2.0-or-later
+ */
+#ifndef ACCEL_TCG_VCPU_STATE_H
+#define ACCEL_TCG_VCPU_STATE_H
+
+#include "hw/core/cpu.h"
+
+#ifdef CONFIG_USER_ONLY
+static inline TaskState *get_task_state(const CPUState *cs)
+{
+    return cs->opaque;
+}
+#endif
+
+#endif