[Debugger] Automatically determine the correct start symbol for a program

[anevilyak]

Currently, the debugger is primarily oriented towards C/C+++, and as such presumes that the starting function will always be main(). Unfortunately, this isn't necessarily the case for other language ABIs such as {Free}Pascal. In the case of a debug executable, this can potentially be inferred from DWARF (still needs to be investigated in the spec), but a mechanism needs to be derived in order to generally guess/infer the target language, and consequently, the correct start symbol.