LoopInfoBase (and DominatorTreeBase) keep a DenseMap fallback for block
types whose GraphTraits lacks getNumber() (#103400); BOLT's
BinaryLoopInfo is one of the last two users.
BinaryBasicBlock already carries a dense [0, size) index (getIndex(),
assigned by updateBBIndices()). Expose it as the GraphTraits node
number, mirroring llvm::BasicBlock/Function.
This makes `GraphHasNodeNumbers<BinaryBasicBlock *>` true, moving BOLT's
LoopInfo and DominatorTree onto the number-indexed (SmallVector) path.
Prerequisite for requiring GraphHasNodeNumbers in LoopInfoBase.
Aided by Claude Opus 4.8
Fangrui Song
be40b8ec4e