[AsmWriterEmitter] Alias priority is ignored

[Rot127]

When alias are emitter the priority is ignored. Only priority = 0 (do not emit) is handled.

Because of this we can not decide, which alias should be emitted in case of a collision.

E.g.

bta eq, 0x400 ; Emitter
beqa 0x400 ; Should be emitter

Possibly it is enough to sort the AliasMap before adding each alias to the IAPrinter:

llvm-capstone/llvm/utils/TableGen/AsmWriterEmitter.cpp

Lines 620 to 645 in 86fea00

	typedef std::set<std::pair<CodeGenInstAlias, int>, AliasPriorityComparator>
	AliasWithPriority;
	std::map<std::string, AliasWithPriority> AliasMap;
	for (Record *R : AllInstAliases) {
	int Priority = R->getValueAsInt("EmitPriority");
	if (Priority < 1)
	continue; // Aliases with priority 0 are never emitted.
	const DagInit *DI = R->getValueAsDag("ResultInst");
	AliasMap[getQualifiedName(DI->getOperatorAsDef(R->getLoc()))].insert(
	std::make_pair(CodeGenInstAlias(R, Target), Priority));
	}
	// A map of which conditions need to be met for each instruction operand
	// before it can be matched to the mnemonic.
	std::map<std::string, std::vector<IAPrinter>> IAPrinterMap;
	std::vector<std::pair<std::string, bool>> PrintMethods;
	// A list of MCOperandPredicates for all operands in use, and the reverse map
	std::vector<const Record*> MCOpPredicates;
	DenseMap<const Record*, unsigned> MCOpPredicateMap;
	for (auto &Aliases : AliasMap) {
	// Collection of instruction alias rules. May contain ambiguous rules.
	std::vector<IAPrinter> IAPs;