util/cpu_detect: Add flag for IBM Z (s390x)

As preparation for changing the behavior of LLVMpipe on IBM Z, add a
flag to detect that platform. As it is always known at compile-time, we
do not add it to the struct for cpu flags to avoid inflating that
struct's size.

Signed-off-by: Marius Hillenbrand <mhillen@linux.ibm.com>
Reviewed-by: Adam Jackson <ajax@redhat.com>
Part-of: <https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/13927>

src/util/u_cpu_detect.h

@@ -35,6 +35,7 @@
 #ifndef _UTIL_CPU_DETECT_H
 #define _UTIL_CPU_DETECT_H
 
+#include <stdbool.h>
 
 #include "pipe/p_config.h"
 #include "util/u_thread.h"
@@ -139,6 +140,16 @@ util_get_cpu_caps(void)
 
 void util_cpu_detect(void);
 
+static inline bool
+util_cpu_caps_has_zarch(void)
+{
+#if defined(PIPE_ARCH_S390)
+   return true;
+#else
+   return false;
+#endif
+}
+
 
 #ifdef	__cplusplus
 }