Adding upstream version 1.34.4.

Signed-off-by: Daniel Baumann <daniel@debian.org>

agent/agent_posix.go

@@ -0,0 +1,19 @@
+//go:build !windows
+
+package agent
+
+import (
+	"os"
+	"os/signal"
+	"syscall"
+)
+
+const flushSignal = syscall.SIGUSR1
+
+func watchForFlushSignal(flushRequested chan os.Signal) {
+	signal.Notify(flushRequested, flushSignal)
+}
+
+func stopListeningForFlushSignal(flushRequested chan os.Signal) {
+	signal.Stop(flushRequested)
+}