Upstream qjs debugger clean

[johnrobinsn]

Integrated quickjs debugger support from https://github.com/koush/vscode-quickjs-debug

Adds the ability to debug javascript with Visual Studio Code (using a quickjs debugger extension).

QuickJS Debugger supports stepping, continue, breakpoints, evaluation, and variable access.

QuickJS Debugger support is not compiled in by default. Given tight integration within the quickjs opcode dispatcher and unsure of performance implications.

To enable support mkdir build; cd build; cmake .. -DCONFIG_QUICKJS_DEBUGGER=ON; make

[saghul]

Did you intend to close this?

[johnrobinsn]

Sorry.... Didn't seem like there was interest... Reopened.

[saghul]

There is interest, sorry! What I don't have much of is time :-)

[tritao]

@saghul Would you still be open to merge this one?

[saghul]

It's still a huge change, but I don't see any movement in upstream QuickJS so yeah.

It does need a rebase though.