llvm-project

d414f29e - [MC/DC] Refactor MCDC::State::Decision. NFC.

[MC/DC] Refactor MCDC::State::Decision. NFC. Introduce `ID` and `InvalidID`. Then `DecisionByStmt` can have three states. * Not assigned if the Stmt(Expr) doesn't exist. * When `DecisionByStmt[Expr]` exists: * Invalid and should be ignored if `ID == Invalid`. * Valid if `ID != Invalid`. Other member will be filled in the Mapper.