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"
```
The nixpkgs-unstable channel's programs.sqlite was used to identify
packages producing exactly one binary, and these automatically added
to their package definitions wherever possible.
This simplifies usages and makes the default value consistent.
In a few cases, the default value was interpreted to be `false`,
but this is useless, because virtually nobody will explicitly
set `allowAliases = true;`.
`nix-build -A gnome2.gtksourceview` fails to build with autoconf 2.70 with the following error:
...
autoreconf: running: intltoolize --copy --force
You should update your 'aclocal.m4' by running aclocal.
autoreconf: running: gtkdocize --copy
Can't exec "gtkdocize": No such file or directory at /nix/store/hm8xfxprfk4l1msb9hpjwgydilbqlvl5-autoconf-2.70/share/autoconf/Autom4te/FileUtils.pm line 293.
autoreconf: error: gtkdocize failed with exit status: 2
gnome2.gtksourceview builds successfully with autoconf 2.69.
