[sanitizer] Add type __sanitizer::ssize

For some targets sptr is mapped to int and ssize_t to long and
sizeof(int)==sizeof(long) holds.  Still, these are distinct types and
type checking may fail.  Therefore, add type __sanitizer::ssize and
typedef it initially to sptr except for s390 -m31 where it is set to
long.

Author: stefan-sf-ibm

compiler-rt/lib/interception/interception.h

@@ -37,7 +37,7 @@
 #endif
 
 #define SIZE_T __sanitizer::usize
-#define SSIZE_T __sanitizer::sptr
+#define SSIZE_T __sanitizer::ssize
 typedef __sanitizer::sptr    PTRDIFF_T;
 typedef __sanitizer::s64     INTMAX_T;
 typedef __sanitizer::u64     UINTMAX_T;

compiler-rt/lib/sanitizer_common/sanitizer_internal_defs.h

@@ -203,6 +203,12 @@ typedef __SIZE_TYPE__ usize;
 typedef uptr usize;
 #endif
 
+#if defined(__s390__) && !defined(__s390x__)
+typedef long ssize;
+#else
+typedef sptr ssize;
+#endif
+
 typedef u64 tid_t;
 
 // ----------- ATTENTION -------------