Assert failure: narrow klass value can never be zero

Test: nsk/jvmti/scenarios/hotswap/HS201/hs201t002
windows-x64-debug

[2018-02-15T05:51:07.23] # Internal Error (t:\workspace\open\src\hotspot\share\oops/klass.inline.hpp:63), pid=3256, tid=12004
[2018-02-15T05:51:07.23] # assert(!is_null(v)) failed: narrow klass value can never be zero