bound breakpoints say they're not bound #71
Description
Sometimes breakpoints say they are not bound, but they do get hit.
Seems related to tracking multiple versions of the same sourcefile as it is recompiled. Something like -- we end up with a mapping like (sourcePath -> JdwpClassfileRef[]) where some of the classfiles for a single sourcepath have been GC'd, but we didn't clean up the JDWP class ref listing, and we report that some of the breakpoints for that sourcepath can't be bound, and vscode interprets that as "not bound".