Add the distribution tag to -print-target-info

Ideally this would also update the `--version` output to be overridden
by `SWIFT_TOOLCHAIN_VERSION`, but unfortunately various tools rely on
the current format (eg. swift-build).

lib/Frontend/ModuleInterfaceLoader.cpp

@@ -932,7 +932,7 @@ class ModuleInterfaceLoaderImpl {
           return std::make_error_code(std::errc::not_supported);
         } else if (isInResourceDir(adjacentMod) &&
                    loadMode == ModuleLoadingMode::PreferSerialized &&
-                   !version::isCurrentCompilerTagged() &&
+                   version::getCurrentCompilerSerializationTag().empty() &&
                    rebuildInfo.getOrInsertCandidateModule(adjacentMod)
                            .serializationStatus !=
                        serialization::Status::SDKMismatch &&