Add prof_leak_error option

The option makes the process to exit with error code 1 if a memory leak
is detected. This is useful for implementing automated tools that rely
on leak detection.

include/jemalloc/internal/prof_externs.h

@@ -12,6 +12,7 @@ extern ssize_t opt_lg_prof_interval; /* lg(prof_interval). */
 extern bool opt_prof_gdump;          /* High-water memory dumping. */
 extern bool opt_prof_final;          /* Final profile dumping. */
 extern bool opt_prof_leak;           /* Dump leak summary at exit. */
+extern bool opt_prof_leak_error;     /* Exit with error code if memory leaked */
 extern bool opt_prof_accum;          /* Report cumulative bytes. */
 extern bool opt_prof_log;            /* Turn logging on at boot. */
 extern char opt_prof_prefix[