In preparation for the deprecation of `stdenv.isX`.
These shorthands are not conducive to cross-compilation because they
hide the platforms.
Darwin might get cross-compilation for which the continued usage of `stdenv.isDarwin` will get in the way
One example of why this is bad and especially affects compiler packages
https://www.github.com/NixOS/nixpkgs/pull/343059
There are too many files to go through manually but a treewide should
get users thinking when they see a `hostPlatform.isX` in a place where it
doesn't make sense.
```
fd --type f "\.nix" | xargs sd --fixed-strings "stdenv.is" "stdenv.hostPlatform.is"
fd --type f "\.nix" | xargs sd --fixed-strings "stdenv'.is" "stdenv'.hostPlatform.is"
fd --type f "\.nix" | xargs sd --fixed-strings "clangStdenv.is" "clangStdenv.hostPlatform.is"
fd --type f "\.nix" | xargs sd --fixed-strings "gccStdenv.is" "gccStdenv.hostPlatform.is"
fd --type f "\.nix" | xargs sd --fixed-strings "stdenvNoCC.is" "stdenvNoCC.hostPlatform.is"
fd --type f "\.nix" | xargs sd --fixed-strings "inherit (stdenv) is" "inherit (stdenv.hostPlatform) is"
fd --type f "\.nix" | xargs sd --fixed-strings "buildStdenv.is" "buildStdenv.hostPlatform.is"
fd --type f "\.nix" | xargs sd --fixed-strings "effectiveStdenv.is" "effectiveStdenv.hostPlatform.is"
fd --type f "\.nix" | xargs sd --fixed-strings "originalStdenv.is" "originalStdenv.hostPlatform.is"
```
with structuredAttrs lists will be bash arrays which cannot be exported
which will be a issue with some patches and some wrappers like cc-wrapper
this makes it clearer that NIX_CFLAGS_COMPILE must be a string as lists
in env cause a eval failure
`uasm` is x86 only.
It seems that in `aarch64-linux` at least, the optimizing build is done
without using any third-party tool (maybe using GCC's own assembly?).
* _7zz: correct license and remove p7zip dependency
The code under Compress/Rar* is licensed under a specific unRAR license
Also Compress/LzfseDecoder.cpp is covered by BSD3
The unRAR code is removed from the `.tar.xz` since the license posits you
agree or remove the code from your hard drive
This adds some complexity to updating 7zz so there is also an update
script
Meta has been updated and tweaked
Source is now downloaded from sourceforge in the `.tar.xz` version to
avoid depending on p7zip
* _7zz: add notice of the license updates and optional unRAR licenced code
Use uasm to compile the optimized code instead of generic C code for
faster operations.
Before:
```
7zz x 10.83s user 0.40s system 98% cpu 11.439 total
```
After:
```
7zz x 6.87s user 0.40s system 98% cpu 7.395 total
```
* 7zz: 21.01 -> 21.04
Also build from source instead of using the binaries.
We cannot (yet) build the fully optimized version as it requires the
ASMC assembler which currently doesn't build with GCC.
