cpu: Introduce cpu_set_cpustate_pointers

Consolidate some boilerplate from foo_cpu_initfn.

Reviewed-by: Alistair Francis <alistair.francis@wdc.com>
Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>

include/exec/cpu-all.h

@@ -371,6 +371,17 @@ int cpu_memory_rw_debug(CPUState *cpu, target_ulong addr,
 
 int cpu_exec(CPUState *cpu);
 
+/**
+ * cpu_set_cpustate_pointers(cpu)
+ * @cpu: The cpu object
+ *
+ * Set the generic pointers in CPUState into the outer object.
+ */
+static inline void cpu_set_cpustate_pointers(ArchCPU *cpu)
+{
+    cpu->parent_obj.env_ptr = &cpu->env;
+}
+
 /**
  * env_archcpu(env)
  * @env: The architecture environment