Can't compile code with C++11 stdlib features

[leha-bot]

I.e.:
Simple program;

`#include

int main()
{
std::to_string(1.0);
return 0;
]`

Is not working. In config GNUCXX_USE_C99 is not defined. If I force define it, then std::to_string become visible, but another functions are not working.

[fornwall]

It's a bug in the Android NDK (which Termux is based on) which hopefully will get fix soon - see #377 for tracking that issue.