Adding an Echo function

[SamuelDeal]

It was a pity not to see what was executed.

So I added an echo function to display int values

File changes:

• corefn.cpp : Added, implementation of the echo function
• Makefile: Modified, corefn.cpp added to compilation process
• main.cpp: Modified, just adding createCoreFunctions function call
• example.txt: Modified, adding an echo for test

ToDo: If you like this push, perhaps llvm tutorial should be updated (not in this repo, so I can't do it, but I'll be glad to do it)

PS: thanks for the doc and source code, great starting point to write my own language

[lsegal]

This is really cool! I don't have time to test this, but I'd be happy to merge it so others can see and play with it. Regarding the guide-- if you provide the extra sections (and/or changes) here or via email I can amend the article to talk about this part. Or you can add a README to this project with more info. The latter might be a lot easier.