lib.licenses.asl20-llvm: replace with separate llvm-exception

This essentially reverts 7ce8e7c4cf90492a631e96bcfe70724104914381

asl20-llvm does not produce a valid SPDX ID, it produces a valid SPDX
Expression. However, this is not what the spdxId field promises.

This is relevant because we cannot produce valid SBOMs (e.g. CycloneDX)
using this field as the schemas for these SBOMs check that the IDs are
valid.

This change leaves us with consistently valid SPDX IDs at the cost
of slightly less convenience.

lib/licenses.nix

···
     fullName = "Apache License 2.0";
   };
 
-  asl20-llvm = {
-    spdxId = "Apache-2.0 WITH LLVM-exception";
-    fullName = "Apache License 2.0 with LLVM Exceptions";
-  };
-
   bitstreamVera = {
     spdxId = "Bitstream-Vera";
     fullName = "Bitstream Vera Font License";
···
   llgpl21 = {
     fullName = "Lisp LGPL; GNU Lesser General Public License version 2.1 with Franz Inc. preamble for clarification of LGPL terms in context of Lisp";
     url = "https://opensource.franz.com/preamble.html";
+  };
+
+  llvm-exception = {
+    spdxId = "LLVM-exception";
+    fullName = "LLVM Exception"; # LLVM exceptions to the Apache 2.0 License
   };
 
   lppl1 = {

pkgs/by-name/co/codechecker/package.nix

···
     homepage = "https://github.com/Ericsson/codechecker";
     changelog = "https://github.com/Ericsson/codechecker/releases/tag/v${version}";
     description = "Analyzer tooling, defect database and viewer extension for the Clang Static Analyzer and Clang Tidy";
-    license = licenses.asl20-llvm;
+    license = with licenses; [
+      asl20
+      llvm-exception
+    ];
     maintainers = with maintainers; [
       zebreus
       felixsinger

pkgs/by-name/en/enzyme/package.nix

···
     description = "High-performance automatic differentiation of LLVM and MLIR";
     maintainers = with lib.maintainers; [ kiranshila ];
     platforms = lib.platforms.all;
-    license = lib.licenses.asl20-llvm;
+    license = with lib.licenses; [
+      asl20
+      llvm-exception
+    ];
   };
 }

pkgs/by-name/ko/kokkos/package.nix

···
     description = "C++ Performance Portability Programming EcoSystem";
     homepage = "https://github.com/kokkos/kokkos";
     changelog = "https://github.com/kokkos/kokkos/blob/${finalAttrs.src.rev}/CHANGELOG.md";
-    license = with licenses; [ asl20-llvm ];
+    license = with licenses; [
+      asl20
+      llvm-exception
+    ];
     maintainers = with maintainers; [ Madouura ];
     platforms = platforms.unix;
     broken = stdenv.hostPlatform.isDarwin;

pkgs/by-name/li/libabigail/package.nix

···
   meta = with lib; {
     description = "ABI Generic Analysis and Instrumentation Library";
     homepage = "https://sourceware.org/libabigail/";
-    license = licenses.asl20-llvm;
+    license = with licenses; [
+      asl20
+      llvm-exception
+    ];
     maintainers = [ ];
     platforms = platforms.linux;
   };

pkgs/by-name/sh/shader-slang/package.nix

···
   meta = {
     description = "A shading language that makes it easier to build and maintain large shader codebases in a modular and extensible fashion";
     homepage = "https://github.com/shader-slang/slang";
-    license = lib.licenses.asl20-llvm;
+    license = with lib.licenses; [
+      asl20
+      llvm-exception
+    ];
     maintainers = with lib.maintainers; [ niklaskorz ];
     mainProgram = "slangc";
     platforms = lib.platforms.all;

pkgs/development/compilers/llvm/common/common-let.nix

···
 rec {
   llvm_meta = {
     license = with lib.licenses; [ ncsa ] ++
-      # Contributions after June 1st, 2024 are only licensed under asl20-llvm:
-      # https://github.com/llvm/llvm-project/pull/92394
-      lib.optional (lib.versionAtLeast release_version "19") asl20-llvm;
+      # Contributions after June 1st, 2024 are only licensed under asl20 and
+      # llvm-exception: https://github.com/llvm/llvm-project/pull/92394
+      lib.optionals (lib.versionAtLeast release_version "19") [ asl20 llvm-exception ];
     maintainers = lib.teams.llvm.members;
 
     # See llvm/cmake/config-ix.cmake.

pkgs/development/libraries/wasilibc/default.nix

···
       rvolosatovs
     ];
     license = with licenses; [
-      asl20-llvm
+      asl20
+      llvm-exception
       mit
     ];
   };