Add size class computation capability.

Add size class computation capability, currently used only as validation
of the size class lookup tables.  Generalize the size class spacing used
for bins, for eventual use throughout the full range of allocation
sizes.

include/jemalloc/internal/jemalloc_internal_macros.h

@@ -39,9 +39,15 @@
 #endif
 
 #define	ZU(z)	((size_t)z)
+#define	ZI(z)	((ssize_t)z)
 #define	QU(q)	((uint64_t)q)
 #define	QI(q)	((int64_t)q)
 
+#define	KZU(z)	ZU(z##ULL)
+#define	KZI(z)	ZI(z##ULL)
+#define	KQU(q)	QU(q##ULL)
+#define	KQI(q)	QI(q##ULL)
+
 #ifndef __DECONST
 #  define	__DECONST(type, var)	((type)(uintptr_t)(const void *)(var))
 #endif