[Serialization] Soft-reject swiftmodules built against a different SDK

Change the way swiftmodules built against a different SDK than their
clients are rejected. This makes them silently ignored when the module
can be rebuilt from their swiftinterface, instead of reporting a hard
error.

rdar://93257769

lib/Serialization/SerializedModuleLoader.cpp

@@ -402,7 +402,7 @@ llvm::ErrorOr<ModuleDependencies> SerializedModuleLoaderBase::scanModuleFile(
   bool isFramework = false;
   serialization::ValidationInfo loadInfo = ModuleFileSharedCore::load(
       modulePath.str(), std::move(moduleBuf.get()), nullptr, nullptr,
-      isFramework, isRequiredOSSAModules(),
+      isFramework, isRequiredOSSAModules(), Ctx.LangOpts.SDKName,
       Ctx.SearchPathOpts.DeserializedPathRecoverer,
       loadedModuleFile);
 
@@ -753,7 +753,7 @@ LoadedFile *SerializedModuleLoaderBase::loadAST(
   serialization::ValidationInfo loadInfo = ModuleFileSharedCore::load(
       moduleInterfacePath, std::move(moduleInputBuffer),
       std::move(moduleDocInputBuffer), std::move(moduleSourceInfoInputBuffer),
-      isFramework, isRequiredOSSAModules(),
+      isFramework, isRequiredOSSAModules(), Ctx.LangOpts.SDKName,
       Ctx.SearchPathOpts.DeserializedPathRecoverer,
       loadedModuleFileCore);
   SerializedASTFile *fileUnit = nullptr;
@@ -1176,7 +1176,8 @@ bool SerializedModuleLoaderBase::canImportModule(ImportPath::Module path,
   // format, if present.
   if (currentVersion.empty() && *unusedModuleBuffer) {
     auto metaData = serialization::validateSerializedAST(
-        (*unusedModuleBuffer)->getBuffer(), Ctx.SILOpts.EnableOSSAModules);
+        (*unusedModuleBuffer)->getBuffer(), Ctx.SILOpts.EnableOSSAModules,
+        Ctx.LangOpts.SDKName);
     currentVersion = metaData.userModuleVersion;
   }