hg: jdk/sandbox: 8251374: jmap -dump could accept invalid options

[chris.hegarty at oracle.com]

Changeset: 95e8aba3b047
Author:    lzang
Date:      2020-08-13 13:57 -0700
URL:       https://hg.openjdk.java.net/jdk/sandbox/rev/95e8aba3b047

8251374: jmap -dump could accept invalid options
Summary: Emit usage(1) in dump() argument loop
Reviewed-by: sspitsyn, phh

! src/jdk.jcmd/share/classes/sun/tools/jmap/JMap.java