GSB: Replace some resolveDependentMemberTypes() calls with getCanonicalTypeInContext()

For now this has no effect since resolveDependentMemberTypes() maps
type parameters to anchors, but I'm going to change it to not do
that.

Change all existing callers of resolveDependentMemberTypes() except
for the one in maybeResolveEquivalenceClass() to use
getCanonicalTypeInContext() instead.

Author: slavapestov

lib/AST/GenericSignatureBuilder.cpp

@@ -3759,8 +3759,7 @@ GenericSignatureBuilder::lookupConformance(CanType dependentType,
 static Type resolveDependentMemberTypes(
                                 GenericSignatureBuilder &builder,
                                 Type type,
-                                ArchetypeResolutionKind resolutionKind
-                                  = ArchetypeResolutionKind::WellFormed) {
+                                ArchetypeResolutionKind resolutionKind) {
   if (!type->hasTypeParameter()) return type;
 
   return type.transformRec([&resolutionKind,
@@ -6195,7 +6194,7 @@ void GenericSignatureBuilder::computeRedundantRequirements() {
 
     if (equivClass.concreteType) {
       Type resolvedConcreteType =
-        resolveDependentMemberTypes(*this, equivClass.concreteType);
+        getCanonicalTypeInContext(equivClass.concreteType, { });
       graph.addConstraintsFromEquivClass(
           *this, equivClass.concreteTypeConstraints,
           RequirementKind::SameType,
@@ -6216,7 +6215,7 @@ void GenericSignatureBuilder::computeRedundantRequirements() {
             if (t->isEqual(resolvedConcreteType))
               return false;
 
-            auto resolvedType = resolveDependentMemberTypes(*this, t);
+            auto resolvedType = getCanonicalTypeInContext(t, { });
             if (resolvedType->isEqual(resolvedConcreteType))
               return false;
 
@@ -6228,7 +6227,7 @@ void GenericSignatureBuilder::computeRedundantRequirements() {
     if (equivClass.superclass) {
       // Resolve any thus-far-unresolved dependent types.
       Type resolvedSuperclass =
-        resolveDependentMemberTypes(*this, equivClass.superclass);
+        getCanonicalTypeInContext(equivClass.superclass, { });
       graph.addConstraintsFromEquivClass(
           *this, equivClass.superclassConstraints,
           RequirementKind::Superclass,
@@ -6249,7 +6248,7 @@ void GenericSignatureBuilder::computeRedundantRequirements() {
             if (t->isEqual(resolvedSuperclass))
               return false;
 
-            Type resolvedType = resolveDependentMemberTypes(*this, t);
+            Type resolvedType = getCanonicalTypeInContext(t, { });
             if (resolvedType->isEqual(resolvedSuperclass))
               return false;
 
@@ -7812,16 +7811,15 @@ void GenericSignatureBuilder::checkConcreteTypeConstraints(
                               EquivalenceClass *equivClass) {
   // Resolve any thus-far-unresolved dependent types.
   Type resolvedConcreteType =
-    resolveDependentMemberTypes(*this, equivClass->concreteType);
+    getCanonicalTypeInContext(equivClass->concreteType, genericParams);
 
   checkConstraintList<Type>(
     genericParams, equivClass->concreteTypeConstraints, RequirementKind::SameType,
     [&](const ConcreteConstraint &constraint) {
       if (constraint.value->isEqual(resolvedConcreteType))
         return true;
 
-      auto resolvedType =
-        resolveDependentMemberTypes(*this, constraint.value);
+      auto resolvedType = getCanonicalTypeInContext(constraint.value, { });
       return resolvedType->isEqual(resolvedConcreteType);
     },
     [&](const Constraint<Type> &constraint) {
@@ -7854,7 +7852,7 @@ void GenericSignatureBuilder::checkSuperclassConstraints(
 
   // Resolve any thus-far-unresolved dependent types.
   Type resolvedSuperclass =
-    resolveDependentMemberTypes(*this, equivClass->superclass);
+    getCanonicalTypeInContext(equivClass->superclass, genericParams);
 
   auto representativeConstraint =
     checkConstraintList<Type>(
@@ -7864,7 +7862,7 @@ void GenericSignatureBuilder::checkSuperclassConstraints(
           return true;
 
         Type resolvedType =
-          resolveDependentMemberTypes(*this, constraint.value);
+          getCanonicalTypeInContext(constraint.value, { });
         return resolvedType->isEqual(resolvedSuperclass);
       },
       [&](const Constraint<Type> &constraint) {
@@ -7888,7 +7886,7 @@ void GenericSignatureBuilder::checkSuperclassConstraints(
   // FIXME: Substitute into the concrete type.
   if (equivClass->concreteType) {
     Type resolvedConcreteType =
-      resolveDependentMemberTypes(*this, equivClass->concreteType);
+      getCanonicalTypeInContext(equivClass->concreteType, genericParams);
     auto existing = equivClass->findAnyConcreteConstraintAsWritten();
     // Make sure the concrete type fulfills the superclass requirement.
     if (!equivClass->superclass->isExactSuperclassOf(resolvedConcreteType)){