This reverts commit 0a944b345e, reversing
changes made to 61733ed6cc.
I dislike these massive stdenv changes with unclear motivation,
especially when they involve gratuitous mass renames like NIX_CC ->
NIX_BINUTILS. The previous such rename (NIX_GCC -> NIX_CC) caused
months of pain, so let's not do that again.
Many (less easily automatically converted) old-style strings
remain.
Where there was any possible ambiguity about the exact version or
variant intended, nothing was changed. IANAL, nor a search robot.
Use `with stdenv.lib` wherever it makes sense.
