[PATCH 4/6] accel/tcg: Declare missing cpu_loop_exit*() stubs

["Philippe Mathieu-Daudé" <f4bug@amsat.org>]

cpu_loop_exit*() functions are declared in accel/tcg/cpu-exec-common.c,
and are not available when TCG accelerator is not built. Add stubs so
linking without TCG succeed.

Problematic files:

- hw/semihosting/console.c in qemu_semihosting_console_inc()
- hw/ppc/spapr_hcall.c in h_confer()
- hw/s390x/ipl.c in s390_ipl_reset_request()
- hw/misc/mips_itu.c

Signed-off-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
---
I suppose the s390x kvm-only build didn't catch this because
of compiler optimization:

in s390_ipl_reset_request():

640     if (tcg_enabled()) {
641         cpu_loop_exit(cs);
642     }

and "sysemu/tcg.h" is:

 13 #ifdef CONFIG_TCG
 14 extern bool tcg_allowed;
 15 #define tcg_enabled() (tcg_allowed)
 16 #else
 17 #define tcg_enabled() 0
 18 #endif
---
 accel/stubs/tcg-stub.c | 10 ++++++++++
 1 file changed, 10 insertions(+)

diff --git a/accel/stubs/tcg-stub.c b/accel/stubs/tcg-stub.c
index 8c18d3eabdd..2304606f8e0 100644
--- a/accel/stubs/tcg-stub.c
+++ b/accel/stubs/tcg-stub.c
@@ -28,3 +28,13 @@ void *probe_access(CPUArchState *env, target_ulong addr, int size,
      /* Handled by hardware accelerator. */
      g_assert_not_reached();
 }
+
+void QEMU_NORETURN cpu_loop_exit(CPUState *cpu)
+{
+    g_assert_not_reached();
+}
+
+void QEMU_NORETURN cpu_loop_exit_restore(CPUState *cpu, uintptr_t pc)
+{
+    g_assert_not_reached();
+}
-- 
2.26.2