stat: add mem stat for jemalloc (#1218)

1, add opts arg for mallctl,dumpinfo
2, collect jemalloc.mem info
3, add debug_console cmd: jmem

Co-authored-by: fx <fx@f.x>

service/debug_console.lua

@@ -156,6 +156,7 @@ function COMMAND.help()
 		debug = "debug address : debug a lua service",
 		signal = "signal address sig",
 		cmem = "Show C memory info",
+		jmem = "Show jemalloc mem stats",
 		ping = "ping address",
 		call = "call address ...",
 		trace = "trace address [proto] [on|off]",
@@ -342,6 +343,15 @@ function COMMAND.cmem()
 	return tmp
 end
 
+function COMMAND.jmem()
+	local info = memory.jestat()
+	local tmp = {}
+	for k,v in pairs(info) do
+		tmp[k] = string.format("%11d  %8.2f Mb", v, v/1048576)
+	end
+	return tmp
+end
+
 function COMMAND.ping(address)
 	address = adjust_address(address)
 	local ti = skynet.now()