lib: Clean up how linux and gcc config is specified

The `platform` field is pointless nesting: it's just stuff that happens
to be defined together, and that should be an implementation detail.

This instead makes `linux-kernel` and `gcc` top level fields in platform
configs. They join `rustc` there [all are optional], which was put there
and not in `platform` in anticipation of a change like this.

`linux-kernel.arch` in particular also becomes `linuxArch`, to match the
other `*Arch`es.

The next step after is this to combine the *specific* machines from
`lib.systems.platforms` with `lib.systems.examples`, keeping just the
"multiplatform" ones for defaulting.

1 files changed, 1 insertions, 1 deletions

diff --git a/pkgs/os-specific/linux/kernel-headers/default.nix b/pkgs/os-specific/linux/kernel-headers/default.nix
index cadf65a7220..d6ed7bccba3 100644
--- a/pkgs/os-specific/linux/kernel-headers/default.nix
+++ b/pkgs/os-specific/linux/kernel-headers/default.nix
@@ -7,7 +7,7 @@ let
     pname = "linux-headers";
     inherit version;
 
-    ARCH = stdenvNoCC.hostPlatform.platform.kernelArch or stdenvNoCC.hostPlatform.kernelArch;
+    ARCH = stdenvNoCC.hostPlatform.linuxArch;
 
     # It may look odd that we use `stdenvNoCC`, and yet explicit depend on a cc.
     # We do this so we have a build->build, not build->host, C compiler.