Replace compiler hack for sync package with //go:linkname

src/runtime/sync.go

@@ -0,0 +1,13 @@
+package runtime
+
+// This file contains support code for the sync package.
+
+//go:linkname registerPoolCleanup sync.runtime_registerPoolCleanup
+func registerPoolCleanup(cleanup func()) {
+	// Ignore.
+}
+
+//go:linkname notifyListCheck sync.runtime_notifyListCheck
+func notifyListCheck(size uintptr) {
+	// Ignore.
+}