Add compiler-rt as split package and other minor changes

pkg.info

@@ -1,7 +1,7 @@
 name: llvm
 description: A collection of modular and reusable compiler and toolchain technologies
 version: 20.1.8
-revision: 4
+revision: 5
 url: https://llvm.org
 license: Apache2-with-llvm-exception
 architecture: any
@@ -23,6 +23,10 @@ downloads:
     extract_to: ${BPM_SOURCE}/tools/clang
     extract_strip_components: 1
     checksum: b7a1b7b0af7b9c7596af6bd46e36d11321926eaa66a7a7dc957ab0a1375ee4b0
+  - url: https://github.com/llvm/llvm-project/releases/download/llvmorg-${BPM_PKG_VERSION}/compiler-rt-${BPM_PKG_VERSION}.src.tar.xz
+    extract_to: ${BPM_SOURCE}/projects/compiler-rt
+    extract_strip_components: 1
+    checksum: 15277402f6fd63397c0917a5c7171cda82d16d226094b828c1ed0f58f73b9c69
   - url: https://github.com/llvm/llvm-project/releases/download/llvmorg-${BPM_PKG_VERSION}/cmake-${BPM_PKG_VERSION}.src.tar.xz
     extract_to: cmake
     extract_strip_components: 1
@@ -37,6 +41,7 @@ split_packages:
       - llvm-libs
       - perl
   - name: llvm-libs
+    description: Runtime libraries for LLVM
     depends:
       - gcc-libs
       - libedit
@@ -44,9 +49,16 @@ split_packages:
       - libxml2
       - zlib
       - zstd
+  - name: compiler-rt
+    description: Compiler runtime libraries for clang
+    depends:
+      - gcc-libs
   - name: clang
     description: C language family frontend for LLVM
     url: https://clang.llvm.org/
     depends:
+      - compiler-rt
       - gcc
+      - llvm-libs
+    optional_depends:
       - llvm