message: fix libegg for mingw64
diff: @@ -30,7 +30,7 @@ namespace dbg
  context.ContextFlags = CONTEXT_FULL;
  // RtlCaptureContext() crashes with heavy optimizations on MinGW 4.7.
  -#if defined(__MINGW32__)
  +#if defined(__MINGW32__) && !defined(_M_AMD64)
  DWORD eip_val = 0;
  DWORD esp_val = 0;
  DWORD ebp_val = 0;
  @@ -42,7 +42,6 @@ namespace dbg
  context.Eip = eip_val;
  context.Esp = esp_val;
  context.Ebp = ebp_val;
  -
  skip = 2;
  #else
  const dll kernel32("kernel32.dll");
  