S/390 CPU fake emulation

Because Qemu currently requires a TCG target to exist and there are quite some
useful helpers here to lay the groundwork for out KVM target, let's create a
stub TCG emulation target for S390X CPUs.

This is required to make tcg happy. The emulation target itself won't work
though.

Signed-off-by: Alexander Graf <[email protected]>
Signed-off-by: Aurelien Jarno <[email protected]>
diff --git a/cpu-exec.c b/cpu-exec.c
index 2c0765c..af4595b 100644
--- a/cpu-exec.c
+++ b/cpu-exec.c
@@ -249,6 +249,7 @@
 #elif defined(TARGET_MIPS)
 #elif defined(TARGET_SH4)
 #elif defined(TARGET_CRIS)
+#elif defined(TARGET_S390X)
     /* XXXXX */
 #else
 #error unsupported target CPU
@@ -673,6 +674,7 @@
 #elif defined(TARGET_SH4)
 #elif defined(TARGET_ALPHA)
 #elif defined(TARGET_CRIS)
+#elif defined(TARGET_S390X)
     /* XXXXX */
 #else
 #error unsupported target CPU