Better error-message when bind fails.

runtime/bin/socket_linux.cc

Index: runtime/bin/socket_linux.cc
diff --git a/runtime/bin/socket_linux.cc b/runtime/bin/socket_linux.cc
index 63935676fab39bc2d4db57a7c24a6b76d21566b7..fc0f1e413c3898c0c15294a4532606328dc17257 100644
--- a/runtime/bin/socket_linux.cc
+++ b/runtime/bin/socket_linux.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);
 }