Convert open options for POSIX open on target platform.

[flackr]

Summary

This moves the conversion of the open options to the target platform. On mac fcntl.h has different values for O_CREAT and O_TRUNC than on linux so by transmitting the standardized lldb open options we can correctly convert them on the target platform.

[ovyalov]

LGTM

source/Plugins/Process/gdb-remote/GDBRemoteCommunicationClient.cpp

 {
     lldb_private::StreamString stream;
     stream.PutCString("vFile:open:");
     std::string path (file_spec.GetPath());
     if (path.empty())
         return UINT64_MAX;
     stream.PutCStringAsRawHex8(path.c_str());
     stream.PutChar(',');
-    const uint32_t posix_open_flags = File::ConvertOpenOptionsForPOSIXOpen(flags);
-    stream.PutHex32(posix_open_flags);
+    stream.PutHex32(flags);
     stream.PutChar(',');
     stream.PutHex32(mode);
     const char* packet = stream.GetData();
     int packet_len = stream.GetSize();
     StringExtractorGDBRemote response;
     if (SendPacketAndWaitForResponse(packet, packet_len, response, false) == PacketResult::Success)
     {
         return ParseHostIOPacketResponse (response, UINT64_MAX, error);

source/Plugins/Process/gdb-remote/GDBRemoteCommunicationServerCommon.cpp

 {
     packet.SetFilePos(::strlen("vFile:open:"));
     std::string path;
     packet.GetHexByteStringTerminatedBy(path,',');
     if (!path.empty())
     {
         if (packet.GetChar() == ',')
         {
-            uint32_t flags = packet.GetHexMaxU32(false, 0);
+            uint32_t flags = File::ConvertOpenOptionsForPOSIXOpen(
+                packet.GetHexMaxU32(false, 0));
             if (packet.GetChar() == ',')
             {
                 mode_t mode = packet.GetHexMaxU32(false, 0600);
                 Error error;
                 int fd = ::open (path.c_str(), flags, mode);
                 const int save_errno = fd == -1 ? errno : 0;
                 StreamString response;
                 response.PutChar('F');