Usage of the C++ stdlib unordered_map in GCC

[Tim Lange]

Hello,

I was preparing a patch for GCC and used the unordered_map from the C++ 
stdlib in my patch. Later on, I noticed that it is used nowhere else 
inside GCC except for some files in the go frontend.

I wondered, now that building GCC requires a C++11 host compiler, 
whether there is a consensus on which data structure implementation is 
preferred. Should I rather use a hash_map instead of an unordered_map 
or is it on my side to decide which one I choose?

- Tim