See previous commit for what was done to `binutils` to make this
possible.
There were some uses of `forcedNativePackages` added. The
combination of overrides with that attribute is highly spooky: it's
often important that if an overridden package comes from it, the
replaced arguments for that package come from it. Long term this
package set and all the spookiness should be gone and irrelevant:
"Move along, nothing to see here!"
No hashes should be changed with this commit
The previous commit redefines `stdenv.cross` for the sake of normal
libaries, the most common use-case of that attribute. Some compilers
however relied on the old definition so we have them use
`targetPlatform` instead. This special casing is fine because we
eventually want to remove `stdenv.cross` and use either `hostPlatform`
or `targetPlatform` instead.