Breakpoint at the last line

[Spown]

Setting a breakpoint on the last line while the adapter is running setts it on the next non-existant line and cant be removed.

Setting the point while the debugger isn't running works ok, though.

[roblourens]

I pushed a fix for one case of this using sourcemaps, but I realized that there's another case without sourcemaps that can't really be fixed by the debug adapter. Filing an issue on vscode.