worker_rlimit_core supports size in K, M, and G

src/core/ngx_cycle.h

diff --git a/src/core/ngx_cycle.h b/src/core/ngx_cycle.h
index e1a35eb..677132e 100644
--- a/src/core/ngx_cycle.h
+++ b/src/core/ngx_cycle.h
@@ -68,8 +68,8 @@
      ngx_int_t                debug_points;
 
      ngx_int_t                rlimit_nofile;
-     ngx_int_t                rlimit_core;
      ngx_int_t                rlimit_sigpending;
+     size_t                   rlimit_core;
 
      int                      priority;