AST: Replace a few mapTypeOutOfContext() calls with ArchetypeType::getInterfaceType()

Author: slavapestov

lib/AST/ASTMangler.cpp

@@ -892,8 +892,7 @@ void ASTMangler::appendType(Type type) {
 
       // Find the archetype information.
       const DeclContext *DC = DeclCtx;
-      auto GTPT = GenericEnvironment::mapTypeOutOfContext(GenericEnv, archetype)
-                      ->castTo<GenericTypeParamType>();
+      auto GTPT = archetype->getInterfaceType()->castTo<GenericTypeParamType>();
 
       // The DWARF output created by Swift is intentionally flat,
       // therefore archetypes are emitted with their DeclContext if

lib/AST/GenericSignatureBuilder.cpp

@@ -2685,8 +2685,7 @@ void ArchetypeType::resolveNestedType(
   auto genericEnv = getGenericEnvironment();
   auto &builder = *genericEnv->getGenericSignatureBuilder();
 
-  Type interfaceType =
-    genericEnv->mapTypeOutOfContext(const_cast<ArchetypeType *>(this));
+  Type interfaceType = getInterfaceType();
   Type memberInterfaceType =
     DependentMemberType::get(interfaceType, nested.first);
   auto equivClass =

lib/AST/SubstitutionMap.cpp

@@ -106,9 +106,8 @@ Type SubstitutionMap::lookupSubstitution(CanSubstitutableType type) const {
         archetype->getParent() != nullptr)
       return Type();
 
-    auto *genericEnv = archetype->getGenericEnvironment();
     type = cast<GenericTypeParamType>(
-      genericEnv->mapTypeOutOfContext(archetype)->getCanonicalType());
+      archetype->getInterfaceType()->getCanonicalType());
   }
 
   // Find the index of the replacement type based on the generic parameter we
@@ -168,8 +167,7 @@ SubstitutionMap::lookupConformance(CanType type, ProtocolDecl *proto) const {
   // If we have an archetype, map out of the context so we can compute a
   // conformance access path.
   if (auto archetype = dyn_cast<ArchetypeType>(type)) {
-    auto *genericEnv = archetype->getGenericEnvironment();
-    type = genericEnv->mapTypeOutOfContext(type)->getCanonicalType();
+    type = archetype->getInterfaceType()->getCanonicalType();
   }
 
   // Error path: if we don't have a type parameter, there is no conformance.