RFR(s):8251848: JMap.histo() and JMap.dump() should parse sub-arguments similarly

[臧琳]

Dear All,
         Please help review the patch of 8251848, Thanks!
         Webrev: http://cr.openjdk.java.net/~lzang/8251848/webrev.00/
         Bug: https://bugs.openjdk.java.net/browse/JDK-8251848
BRs,
Lin