8076236: VM permits illegal flags for class init method
Summary: Move check for multiple access flags so that it also covers instance initialization methods
Reviewed-by: ctornqvi, lfoltan
^build/
^dist/
^webrev
/nbproject/private/
^src/share/tools/hsdis/build/
^src/share/tools/IdealGraphVisualizer/[a-zA-Z0-9]*/build/
^src/share/tools/IdealGraphVisualizer/build/
^src/share/tools/IdealGraphVisualizer/dist/
^.hgtip
.DS_Store