testing.B.Loop() standardization and StackAsync.Debug improvement (#156)

* testing.B.Loop() standardization and StackAsync.Debug heap debugging improvement

* apply @MDr164 fixes

* @MDr164 great suggestions to prevent panic and print correct mallocs

internal/debug_noheaplog.go

@@ -21,3 +21,9 @@ func LogAttrs(l *slog.Logger, level slog.Level, msg string, attrs ...slog.Attr)
 		l.LogAttrs(context.Background(), level, msg, attrs...)
 	}
 }
+
+func logAttrsAndAllocs(allocmsg string, l *slog.Logger, level slog.Level, msg string, attrs ...slog.Attr) {
+	LogAllocs(allocmsg)
+	LogAttrs(l, level, msg, attrs...)
+	LogAllocs(msg) // Should not log again unless LogAttrs allocated.
+}