6822407: heapOopSize lookup is incorrect in Serviceability Agent.
Summary: heapOopSize symbol should be declared as constant in vmStructs and should not be looked up in readVMIntConstants().
Reviewed-by: never, swamyv, coleenp
^build/
^dist/
^nbproject/private/
^src/share/tools/hsdis/bin/
^src/share/tools/IdealGraphVisualizer/[a-zA-Z0-9]*/build/
^src/share/tools/IdealGraphVisualizer/build/
^src/share/tools/IdealGraphVisualizer/dist/