Improved stack traces

[morganthomas]

As a leanVM user, I would like to be able to instruct the compiler to output the entire call stack for my program(s), organized by the caller/callee relation, so that I can more easily debug my program(s).

Acceptance criteria

• By setting an environment variable, a command line flag, or an argument to compile_and_run, I can output a stack trace for my program in the event it fails.
• The stack trace is organized hierarchically according to the caller/callee relation.
• The stack trace includes the entire current call stack, from the currently executing function to the main function.
• The stack trace includes accurate line numbers and pc values.