[comment500]

ChakraCore, the former JavaScript engine of Microsoft's Edge browser, has in its repo a decent high-level description of how its JIT compilation is integrated: https://github.com/chakra-core/ChakraCore/wiki/Architecture-...

I found the source code to be quite readable too, last time I delved into it. Also its command line tool ("ch"), when compiled in debug mode, has loads of options available to show what it's doing internally when it executes a JavaScript program.