Koopa v0.0.2

Added

• More re-imports.
• Example opt, brainfuck and interpreter.
• Method Value::uses and iterator of Use.
• Method Type::size.
• Method Generator::new_with_visitor for visitors that has internal state.
• ValueCursorMut for instruction list in basic blocks.

Changed

• Replaced all debug_asserts with asserts.
• Removed all unary operations.
• Signature of method Driver::from_path and Generator::from_path.
• Signature of method Value::replace_all_uses_with.

Fixed

• Fault about generating branch instructions into LLVM IR.
• Fault about creating file in Generator::from_path.
• Fault about generating Koopa IR and LLVM IR.
• Infinite loop problem in Builder::generate_local_symbol.
• Fault about updating BasicBlockInner::preds.