debug/log: Add benchmarks for calling the logging function

Add some benchmarks for calling Log, both with a static string
along with calling the ID.Str and ID.String functions.

internal/debug/log_test.go

@@ -0,0 +1,34 @@
+package debug_test
+
+import (
+	"github.com/restic/restic/internal/debug"
+	"github.com/restic/restic/internal/restic"
+
+	"testing"
+)
+
+func BenchmarkLogStatic(b *testing.B) {
+	for i := 0; i < b.N; i++ {
+		debug.Log("Static string")
+	}
+}
+
+func BenchmarkLogIDStr(b *testing.B) {
+	id := restic.NewRandomID()
+
+	b.ResetTimer()
+
+	for i := 0; i < b.N; i++ {
+		debug.Log("id: %v", id.Str())
+	}
+}
+
+func BenchmarkLogIDString(b *testing.B) {
+	id := restic.NewRandomID()
+
+	b.ResetTimer()
+
+	for i := 0; i < b.N; i++ {
+		debug.Log("id: %v", id.String())
+	}
+}