Better error-message when bind fails.

runtime/bin/socket_android.cc

Index: runtime/bin/socket_android.cc
diff --git a/runtime/bin/socket_android.cc b/runtime/bin/socket_android.cc
index b3e3fc4cb100b04e6d45110dca6d2f24b802cd62..caddb3a0de1384dabc768449e51060b2a815146d 100644
--- a/runtime/bin/socket_android.cc
+++ b/runtime/bin/socket_android.cc
@@ -101,6 +101,12 @@ intptr_t Socket::CreateBindConnect(const RawAddr& addr,
 }
 
 
+bool Socket::IsBindError(intptr_t error_number) {
+  return error_number == EADDRINUSE || error_number == EADDRNOTAVAIL ||
+      error_number == EINVAL;
+}
+
+
 intptr_t Socket::Available(intptr_t fd) {
   return FDUtils::AvailableBytes(fd);
 }