Use table lookup for run_quantize_{floor,ceil}().

Reduce run quantization overhead by generating lookup tables during
bootstrapping, and using the tables for all subsequent run quantization.

include/jemalloc/internal/arena.h

@@ -494,7 +494,7 @@ extern size_t		map_bias; /* Number of arena chunk header pages. */
 extern size_t		map_misc_offset;
 extern size_t		arena_maxrun; /* Max run size for arenas. */
 extern size_t		large_maxclass; /* Max large size class. */
-extern size_t		small_maxrun; /* Max run size for small size classes. */
+extern size_t		run_quantize_max; /* Max run_quantize_*() input. */
 extern unsigned		nlclasses; /* Number of large size classes. */
 extern unsigned		nhclasses; /* Number of huge size classes. */
 

include/jemalloc/internal/private_symbols.txt

@@ -447,6 +447,7 @@ rtree_val_read
 rtree_val_write
 run_quantize_ceil
 run_quantize_floor
+run_quantize_max
 s2u
 s2u_compute
 s2u_lookup