[Serialization] Ensure we run InheritedTypeRequest before serializing inherited type

When using `-experimental-skip-all-function-bodies` we don’t run the `TypeCheckSourceFileRequest` and thus don’t go through the decl checker, which calls `InheritedTypeRequest` on all inheritance clauses. This means that the inherited entries are not populated by the time we serialize the module. Trigger the computation of inherited entries by calling `InheritedTypeRequest` during serialization.

Unfortunately, we can’t use the type returned by `getResolvedType` for the serialization because `getResolvedType` returns an inverted protocol type for suppressed conformances but during serialization, we want to serialize the suppressed type with a `isSuppressedBit`. We thus need to call `getEntry(i).getType()` again to get the type to serialize.

rdar://141440011

Author: ahoppen

lib/Serialization/Serialization.cpp

@@ -4080,7 +4080,15 @@ class Serializer::DeclSerializer : public DeclVisitor<DeclSerializer> {
   /// \returns the number of entries added.
   size_t addInherited(InheritedTypes inheritedEntries,
                       SmallVectorImpl<uint64_t> &result) {
-    for (const auto &inherited : inheritedEntries.getEntries()) {
+    for (size_t i = 0; i < inheritedEntries.size(); ++i) {
+      // Ensure that we run the `InheritedTypeRequest` before getting the
+      // inherited type. We serialize the inherited type into the module
+      // because we serialize whether the conformance is suppressed as a
+      // separate bit instead of inside the inherited type itself. We thus need
+      // to get the type to serialize using a subsequent call to
+      // `getEntry(i).getType()` (see `InheritedTypeRequest::cacheResult`).
+      (void)inheritedEntries.getResolvedType(i);
+      const InheritedEntry &inherited = inheritedEntries.getEntry(i);
       assert(!inherited.getType() || !inherited.getType()->hasArchetype());
       uint64_t typeRef = S.addTypeRef(inherited.getType());
       uint64_t originalTypeRef = typeRef;

test/IDE/rdar141440011.swift

@@ -0,0 +1,8 @@
+public protocol MyProto {}
+public struct MyStruct: MyProto {}
+
+// RUN: %empty-directory(%t)
+// RUN: %swift -emit-module -o %t/swift_mod.swiftmodule %s -parse-as-library -experimental-skip-all-function-bodies -experimental-skip-non-exportable-decls -experimental-lazy-typecheck -target arm64-apple-macosx13.0
+// RUN: %target-swift-synthesize-interface -module-name swift_mod -I %t -o - -target arm64-apple-macosx13.0 | %FileCheck %s
+
+// CHECK: public struct MyStruct : swift_mod.MyProto