linux-user/mips64: Restore setup_frame() for o32 ABI

64-bit MIPS targets lost setup_frame() during the refactor in commit
8949bef. Restore it declaring TARGET_ARCH_HAS_SETUP_FRAME, to be
able to build the o32 ABI target.

Fixes: 8949bef ("linux-user: move mips/mips64 signal.c parts to mips directory")
Signed-off-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Reviewed-by: Laurent Vivier <laurent@vivier.eu>
Message-Id: <20201119161710.1985083-2-f4bug@amsat.org>
Signed-off-by: Laurent Vivier <laurent@vivier.eu>

linux-user/mips64/target_signal.h

@@ -67,4 +67,8 @@ typedef struct target_sigaltstack {
 #define TARGET_MINSIGSTKSZ    2048
 #define TARGET_SIGSTKSZ       8192
 
+#if defined(TARGET_ABI_MIPSO32)
+/* compare linux/arch/mips/kernel/signal.c:setup_frame() */
+#define TARGET_ARCH_HAS_SETUP_FRAME
+#endif
 #endif /* MIPS64_TARGET_SIGNAL_H */