Generic implementation of console I/O instructions. Should work on all ANSI C systems.
Pop a value off the back of the stack (or just read it from the given BasePointer-relative address) and present it to the user in string form. (PRINT_VALUE_INSTR)
param1 - If this is BACK_OF_STACK, we're supposed to pop the last item off the stack. Otherwise, this is a basePtr-relative address where a value will just be read.