Code generator: don't erase already generated functions

[maximilien-noal]

Remember: There is 4 scripts for Ghidra.

• the import symbols py script to import the names of the functions and labels that spice86 generates
  • the spice86 script for generating references to tell ghidra where the indirect calls and jumps go (important otherwise it won't see the code)
  • the spice86 script to rename the functions inferred by ghidra so that the generator uses them and can deduce the segments
  • finally the generator the first 3 help you to have a ghidra file with more information and not to do too much work by hand

the generator works better with a clean slate.

[maximilien-noal]

When Cryogenic is run with the right parameters (see the Spice86 README for details), it generates a CSV file that indicates which functions are overriden by .NET code.

By reading it in the C# code generator written in Java, we could avoid the generation of those already generated functions.

[maximilien-noal]

Maybe add the fact that a function is overriden or not in the executionflow.json file, so the Ghidra code generator doesn't need to read several files.

[maximilien-noal]

Completed by @kevinferrare