Using C++'11 language features in LLVM itself

Following the feedback from David, here is an updated list of the profiles,
taking into account deprecated versions of the specifications of the lambdas
and r-values that might be of interest. As before, they are duly annotated
with a remark.

It's much smaller than these headline features, but how about commas
at the end of enum lists? Could be useful for keeping revision-control
logs in good shape.

At least g++ accepts them even in C++98 mode.