AST: Fix confusion when builtin conformance passed to registerProtocolConformance()

Author: slavapestov

include/swift/AST/Decl.h

@@ -4219,7 +4219,7 @@ class NominalTypeDecl : public GenericTypeDecl, public IterableDeclContext {
   ///
   /// This is used by deserialization of module files to report
   /// conformances.
-  void registerProtocolConformance(ProtocolConformance *conformance,
+  void registerProtocolConformance(NormalProtocolConformance *conformance,
                                    bool synthesized = false);
 
   void setConformanceLoader(LazyMemberLoader *resolver, uint64_t contextData);

lib/AST/ConformanceLookupTable.cpp

@@ -174,7 +174,7 @@ void ConformanceLookupTable::forEachInStage(ConformanceStage stage,
     if (loader.first) {
       SmallVector<ProtocolConformance *, 2> conformances;
       loader.first->loadAllConformances(nominal, loader.second, conformances);
-      loadAllConformances(nominal, conformances);
+      registerProtocolConformances(nominal, conformances);
     }
 
     nominalFunc(nominal);
@@ -202,7 +202,7 @@ void ConformanceLookupTable::forEachInStage(ConformanceStage stage,
     if (loader.first) {
       SmallVector<ProtocolConformance *, 2> conformances;
       loader.first->loadAllConformances(next, loader.second, conformances);
-      loadAllConformances(next, conformances);
+      registerProtocolConformances(next, conformances);
       for (auto conf : conformances) {
         protocols.push_back(
             {conf->getProtocol(), SourceLoc(), SourceLoc(), SourceLoc()});
@@ -433,19 +433,17 @@ void ConformanceLookupTable::updateLookupTable(NominalTypeDecl *nominal,
   }
 }
 
-void ConformanceLookupTable::loadAllConformances(
+void ConformanceLookupTable::registerProtocolConformances(
        DeclContext *dc,
        ArrayRef<ProtocolConformance*> conformances) {
   // If this declaration context came from source, there's nothing to
   // do here.
-  if (dc->getParentSourceFile() ||
-      dc->getParentModule()->isBuiltinModule()) {
-    return;
-  }
+  assert(!dc->getParentSourceFile() &&
+         !dc->getParentModule()->isBuiltinModule());
 
   // Add entries for each loaded conformance.
   for (auto conformance : conformances) {
-    registerProtocolConformance(conformance);
+    registerProtocolConformance(dc, conformance);
   }
 }
 
@@ -1019,10 +1017,9 @@ void ConformanceLookupTable::addSynthesizedConformance(
 }
 
 void ConformanceLookupTable::registerProtocolConformance(
-       ProtocolConformance *conformance,
+       DeclContext *dc, ProtocolConformance *conformance,
        bool synthesized) {
   auto protocol = conformance->getProtocol();
-  auto dc = conformance->getDeclContext();
   auto nominal = dc->getSelfNominalTypeDecl();
 
   // If there is an entry to update, do so.

lib/AST/ConformanceLookupTable.h

@@ -459,10 +459,10 @@ class ConformanceLookupTable : public ASTAllocated<ConformanceLookupTable> {
   /// Update a lookup table with conformances from newly-added extensions.
   void updateLookupTable(NominalTypeDecl *nominal, ConformanceStage stage);
 
-  /// Load all of the protocol conformances for the given (serialized)
+  /// Register deserialized protocol conformances for the given (serialized)
   /// declaration context.
-  void loadAllConformances(DeclContext *dc,
-                           ArrayRef<ProtocolConformance *> conformances);
+  void registerProtocolConformances(DeclContext *dc,
+                                  ArrayRef<ProtocolConformance *> conformances);
 
 public:
   /// Create a new conformance lookup table.
@@ -477,7 +477,8 @@ class ConformanceLookupTable : public ASTAllocated<ConformanceLookupTable> {
                                  DeclContext *conformanceDC);
 
   /// Register an externally-supplied protocol conformance.
-  void registerProtocolConformance(ProtocolConformance *conformance,
+  void registerProtocolConformance(DeclContext *dc,
+                                   ProtocolConformance *conformance,
                                    bool synthesized = false);
 
   /// Look for conformances to the given protocol.

lib/AST/ProtocolConformance.cpp

@@ -1195,9 +1195,10 @@ void NominalTypeDecl::getImplicitProtocols(
 }
 
 void NominalTypeDecl::registerProtocolConformance(
-       ProtocolConformance *conformance, bool synthesized) {
+       NormalProtocolConformance *conformance, bool synthesized) {
   prepareConformanceTable();
-  ConformanceTable->registerProtocolConformance(conformance, synthesized);
+  auto *dc = conformance->getDeclContext();
+  ConformanceTable->registerProtocolConformance(dc, conformance, synthesized);
 }
 
 ArrayRef<ValueDecl *>