Revert "Revert "[Serialization] Serialize isUserAccessible on functions""

This reverts commit bf25a01.

Author: xymus

lib/Serialization/Deserialization.cpp

@@ -2995,6 +2995,7 @@ class DeclDeserializer {
     DeclID accessorStorageDeclID;
     bool overriddenAffectsABI, needsNewVTableEntry, isTransparent;
     DeclID opaqueReturnTypeID;
+    bool isUserAccessible;
     ArrayRef<uint64_t> nameAndDependencyIDs;
 
     if (!isAccessor) {
@@ -3012,6 +3013,7 @@ class DeclDeserializer {
                                           rawAccessLevel,
                                           needsNewVTableEntry,
                                           opaqueReturnTypeID,
+                                          isUserAccessible,
                                           nameAndDependencyIDs);
     } else {
       decls_block::AccessorLayout::readRecord(scratch, contextID, isImplicit,
@@ -3192,6 +3194,7 @@ class DeclDeserializer {
     fn->setForcedStaticDispatch(hasForcedStaticDispatch);
     ctx.evaluator.cacheOutput(NeedsNewVTableEntryRequest{fn},
                               std::move(needsNewVTableEntry));
+    fn->setUserAccessible(isUserAccessible);
 
     if (opaqueReturnTypeID) {
       ctx.evaluator.cacheOutput(

lib/Serialization/ModuleFormat.h

@@ -1308,6 +1308,7 @@ namespace decls_block {
     AccessLevelField, // access level
     BCFixed<1>,   // requires a new vtable slot
     DeclIDField,  // opaque result type decl
+    BCFixed<1>,   // isUserAccessible?
     BCArray<IdentifierIDField> // name components,
                                // followed by TypeID dependencies
     // The record is trailed by:

lib/Serialization/Serialization.cpp

@@ -3437,6 +3437,7 @@ class Serializer::DeclSerializer : public DeclVisitor<DeclSerializer> {
                            rawAccessLevel,
                            fn->needsNewVTableEntry(),
                            S.addDeclRef(fn->getOpaqueResultTypeDecl()),
+                           fn->isUserAccessible(),
                            nameComponentsAndDependencies);
 
     writeGenericParams(fn->getGenericParams());

test/IDE/Inputs/complete_user_accessibility_helper.swift

@@ -0,0 +1,3 @@
+public enum MyEnum {
+  case foo, bar
+}

test/IDE/complete_user_accessible.swift

@@ -0,0 +1,19 @@
+/// Check that serialized non user accessible functions are not autocompleted.
+/// rdar://problem/53891642
+/// SR-7460
+
+// RUN: %empty-directory(%t)
+// RUN: %target-swift-frontend -emit-module %S/Inputs/complete_user_accessibility_helper.swift -module-name helper -emit-module-path %t/helper.swiftmodule
+// RUN: %target-swift-ide-test -code-completion -source-filename %s -code-completion-token=USER-ACCESS -I %t | %FileCheck %s -check-prefix=USER-ACCESS
+
+import helper
+
+{
+  _ = MyEnum.#^USER-ACCESS^#
+// USER-ACCESS:          Begin completions
+// USER-ACCESS-DAG:      Keyword[self]/CurrNominal:          self[#MyEnum.Type#]; name=self
+// USER-ACCESS-DAG:      Keyword/CurrNominal:                Type[#MyEnum.Type#]; name=Type
+// USER-ACCESS-DAG:      Decl[EnumElement]/CurrNominal:      foo[#MyEnum#]; name=foo
+// USER-ACCESS-DAG:      Decl[EnumElement]/CurrNominal:      bar[#MyEnum#]; name=bar
+// USER-ACCESS-NOT:      __derived_enum_equals
+}