ir: Initial API stubs.
grammer: Remove latex version of the grammar in favor of a simpler format for the task.
ir: Add linkage type.
ir: Make Linkage a regular 8-bit integer instead of a 16-bit bitfield.
ir: Add calling conventions type.
ir: Add type for visibility styles.
ir: Use Linkage, Visibility and CC instead of Link, Vis and Call respectively.
ir: Remove temporary TODOs. At this stage there would be too many to track.
ir: Add conditional and unconditional branch instructions.
ir: Add type for return instruction.
ir: Rearrange instruction definitions.
ir: Add switch instruction.
ir: Add add instruction.
ir: Add fadd instruction.
ir: Add sub instruction.
ir: Add fsub instruction.
ir: Add mul instruction.
ir: Add fmul instruction.
ir: Add udiv and sdiv instructions.
ir: Add fdiv, urem and srem instructions.