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.
(cherry picked from commit ec8d41f08c)
Factor a binutils wrapper out of cc-wrapper. While only LD is wrapped,
the setup hook defines environment variables on behalf of other
utilites.
(cherry picked from commit 40e9b2a7e6)
