Switch to new download format and update source.sh script

pkg.info

@@ -1,18 +1,52 @@
 name: llvm
 description: A collection of modular and reusable compiler and toolchain technologies
 version: 20.1.8
-revision: 3
+revision: 4
 url: https://llvm.org
 license: Apache2-with-llvm-exception
 architecture: any
-make_depends: ["cmake","libffi","ncurses","ninja","python3","zlib","zstd"]
 type: source
+make_depends:
+  - cmake
+  - libffi
+  - ncurses
+  - ninja
+  - python3
+  - zlib
+  - zstd
+downloads:
+  - url: https://github.com/llvm/llvm-project/releases/download/llvmorg-${BPM_PKG_VERSION}/llvm-${BPM_PKG_VERSION}.src.tar.xz
+    extract_to: ${BPM_SOURCE}
+    extract_strip_components: 1
+    checksum: e1363888216b455184dbb8a74a347bf5612f56a3f982369e1cba6c7e0726cde1
+  - url: https://github.com/llvm/llvm-project/releases/download/llvmorg-${BPM_PKG_VERSION}/clang-${BPM_PKG_VERSION}.src.tar.xz
+    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}/cmake-${BPM_PKG_VERSION}.src.tar.xz
+    extract_to: cmake
+    extract_strip_components: 1
+    checksum: 3319203cfd1172bbac50f06fa68e318af84dcb5d65353310c0586354069d6634
+  - url: https://github.com/llvm/llvm-project/releases/download/llvmorg-${BPM_PKG_VERSION}/third-party-${BPM_PKG_VERSION}.src.tar.xz
+    extract_to: third-party
+    extract_strip_components: 1
+    checksum: 9a4e452a8163732d417db067a89190fcda823cb3aa33199e834ac7c028923f4b
 split_packages:
   - name: llvm
-    depends: ["llvm-libs","perl"]
+    depends:
+      - llvm-libs
+      - perl
   - name: llvm-libs
-    depends: ["gcc-libs","libedit","libffi","libxml2","zlib","zstd"]
+    depends:
+      - gcc-libs
+      - libedit
+      - libffi
+      - libxml2
+      - zlib
+      - zstd
   - name: clang
     description: C language family frontend for LLVM
     url: https://clang.llvm.org/
-    depends: ["gcc","llvm"]
+    depends:
+      - gcc
+      - llvm