RequirementMachine: Remove PropertyMap::ConcreteConformances

Author: slavapestov

lib/AST/RequirementMachine/ConcreteTypeWitness.cpp

@@ -132,9 +132,7 @@ void PropertyMap::concretizeNestedTypesFromConcreteParent(
     //
     // This occurs when a pair of rules are inherited from the property map
     // entry for this key's suffix.
-    auto pair = std::make_pair(concreteRuleID, conformanceRuleID);
-    auto found = ConcreteConformances.find(pair);
-    if (found != ConcreteConformances.end())
+    if (!checkRulePairOnce(concreteRuleID, conformanceRuleID))
       continue;
 
     // FIXME: Either remove the ModuleDecl entirely from conformance lookup,
@@ -168,13 +166,6 @@ void PropertyMap::concretizeNestedTypesFromConcreteParent(
     // opaque result type?
     assert(!conformance.isAbstract());
 
-    // Save this conformance for later.
-    auto *concrete = conformance.getConcrete();
-    auto inserted = ConcreteConformances.insert(
-        std::make_pair(pair, concrete));
-    assert(inserted.second);
-    (void) inserted;
-
     auto concreteConformanceSymbol = Symbol::forConcreteConformance(
         concreteType, substitutions, proto, Context);
 

lib/AST/RequirementMachine/PropertyMap.h

@@ -174,12 +174,6 @@ class PropertyMap {
   // To avoid wasted work from re-introducing the same induced rules,
   // we track the rules we've seen already on previous builds.
 
-  /// Maps a pair of rules where the first is a conformance rule and the
-  /// second is a superclass or concrete type rule, to a concrete
-  /// conformance.
-  llvm::DenseMap<std::pair<unsigned, unsigned>, ProtocolConformance *>
-      ConcreteConformances;
-
   /// Superclass requirements always imply a layout requirement, and
   /// concrete type requirements where the type is a class imply a
   /// superclass requirement.