llvmPackages_{20,21}.libclc: reenable and update patches

pkgs/development/compilers/llvm/20/libclc/use-default-paths.patch

@@ -0,0 +1,22 @@
+From e8b910246d0c7c3d9fff994f71c6f8a48ec09a50 Mon Sep 17 00:00:00 2001
+From: Tristan Ross <tristan.ross@midstall.com>
+Date: Sat, 24 Aug 2024 19:56:24 -0700
+Subject: [PATCH] [libclc] use default paths with find_program when possible
+
+---
+ libclc/CMakeLists.txt | 4 ++--
+ 1 file changed, 1 insertions(+), 1 deletions(-)
+
+diff --git a/CMakeLists.txt b/CMakeLists.txt
+index 02bb859ae8590b..6bcd8ae52a5794 100644
+--- a/CMakeLists.txt
++++ b/CMakeLists.txt
+@@ -55,7 +55,7 @@ if( LIBCLC_STANDALONE_BUILD OR CMAKE_SOURCE_DIR STREQUAL CMAKE_CURRENT_SOURCE_DI
+   # Import required tools
+   if( NOT EXISTS ${LIBCLC_CUSTOM_LLVM_TOOLS_BINARY_DIR} )
+     foreach( tool IN ITEMS clang llvm-as llvm-link opt )
+-      find_program( LLVM_TOOL_${tool} ${tool} PATHS ${LLVM_TOOLS_BINARY_DIR} NO_DEFAULT_PATH )
++      find_program( LLVM_TOOL_${tool} ${tool} PATHS ${LLVM_TOOLS_BINARY_DIR} )
+       set( ${tool}_exe ${LLVM_TOOL_${tool}} )
+       set( ${tool}_target )
+     endforeach()

pkgs/development/compilers/llvm/21/libclc/gnu-install-dirs.patch

@@ -0,0 +1,8 @@
+--- a/libclc.pc.in
++++ b/libclc.pc.in
+@@ -1,4 +1,4 @@
+-libexecdir=@CMAKE_INSTALL_PREFIX@/@CMAKE_INSTALL_DATADIR@/clc
++libexecdir=@CMAKE_INSTALL_FULL_DATADIR@/clc
+ 
+ Name: libclc
+ Description: Library requirements of the OpenCL C programming language

pkgs/development/compilers/llvm/common/default.nix

@@ -484,7 +484,7 @@ let
     }
     //
       lib.optionalAttrs
-        (lib.versionAtLeast metadata.release_version "16" && lib.versionOlder metadata.release_version "20")
+        (lib.versionAtLeast metadata.release_version "16" && lib.versionOlder metadata.release_version "22")
         {
           libclc = callPackage ./libclc { };
         }

pkgs/development/compilers/llvm/common/libclc/default.nix

@@ -50,7 +50,7 @@ stdenv.mkDerivation (finalAttrs: {
   ];
 
   patches = [
-    ./libclc-gnu-install-dirs.patch
+    (getVersionFile "libclc/gnu-install-dirs.patch")
   ]
   # LLVM 19 changes how host tools are looked up.
   # Need to remove NO_DEFAULT_PATH and the PATHS arguments for find_program

pkgs/development/compilers/llvm/common/patches.nix

@@ -236,7 +236,23 @@
   "libclc/use-default-paths.patch" = [
     {
       after = "19";
+      before = "20";
       path = ../19;
     }
+    {
+      after = "20";
+      path = ../20;
+    }
+  ];
+  "libclc/gnu-install-dirs.patch" = [
+    {
+      after = "16";
+      before = "21";
+      path = ../16;
+    }
+    {
+      after = "21";
+      path = ../21;
+    }
   ];
 }