SCI: adds support for debugging/executing kernel calls

[deckarep]

Introduces a new kerncall kernel/sub command to the debugger console only to aid in debugging all related SCI games. Similar in vein to using the send command.

Example within the SCI debug console:

) kerncall Random 4 8
kernel call result is: 0000:0008

• Additionally, adds a few annotations and clarifications when you are viewing decimal/hex segment ids.
• Lastly, to be more clear renames command: functions to kernfunctions to list all kernel routines.

[deckarep]

Hi ScummVM devs, there’s certainly no rush here but I’m hoping this is a small enough, welcome enhancement to the debugging tools for SCI.

Please let me know if I can provide more context on why I thought to contribute this change. Also I welcome any comments to improve this code.

[sluicebox]

Wow! Congratulations, this is a great and worthy new debug command. I will use it all the time. I think I've wished for this before?

• Zero-argument calls should work; some functions don't have any, or they're optional. For example, kerncall GameIsRestarting should work. (That one is safe to call from anywhere, it returns a flag)
• This is so useful that we'll get sick of typing kerncall every time, let's also add a kc alias. You've earned it!
• kernfunctions is an okay name for consistency, but let's also keep the functions alias for those of us that have built up muscle memory. =)

The command appears to work great, so once the little things are done I'll merge it. @bluegr mentioned to me earlier that this looked good and useful. He's right!

If this weren't debug code, I'd ask for the cmdKernelFunctions cleanup to be moved to a separate commit to keep things hyper organized for posterity, but the bar is a little lower in console.cpp, so no need for more work.

[deckarep]

Alright!

Excellent comments and it’s super appreciated. I will get on this today!

[deckarep]

@sluicebox,

Please see this updated review with your comments addressed:

• Aliases added for kerncall -> kc.
• Aliases added for kernfunctions -> functions.
• 0 argument kernel calls now supported. Good catch!

Lastly, I made sure to rebase and squash with the latest ScummVM code. Feel free to let me know if you'd like more tweaks.

Cheers!

[sluicebox]

Looks great!

Sorry, but I failed to click the shiny Review button earlier, so my inline comments were invisible to you. You should be able to see them now.

[deckarep]

@sluicebox - ok, for the 2nd round of comments this PR has been rebased against master and squashed.

[sluicebox]

Excellent, thank you for your hard work. Looking forward to kc'ing all over the place. Merging with conviction!