elna/TODO

# Intermediate code generation

- To access named parameters and local variables inside a procedure, IR should
  be able to reference them. During the generation the needed information (e.g.
  offsets or registers) can be extracted from the symbol table and saved in the
  operands.

# ELF generation

- Don't ignore relocations where the symbol is not defined in the symbol table.
  Report an error about an undefined symbol.
- JumpLabels inside functions are encoded as functions. Distinguish between
  labels (e.g. .A0 or .L0) and global functions. Lables are NOTYPE LOCAL.
- Sort the symbols so that local symbols come first. Some table header had a
  number specifiying the index of the first non-local symbol. Adjust that number.


# Name analysis

- Format error messages.
- Return non-zero error code on errors.

# Register allocation

- Each temporary variales gets a tn register where n is the variable index. If
  there more variables the allocation will fail with out of bounds runtime
  error. Implement spill over.

# Prarsing and abstract syntax tree

- Parse signed hexadecimal numbers.

# Other

- Type analysis.
- Generate a call to _divide_by_zero_error on RiscV.