[llvm] [llvm][release] Add links to automatically built packages (PR #147719)

[David Spickett via llvm-commits]

================
@@ -45,9 +45,26 @@ def create_release(repo, release, tag=None, name=None, message=None):
         # Note that these lines are not length limited because if we do so, GitHub
         # assumes that should be how it is laid out on the page. We want GitHub to
         # do the reflowing for us instead.
+        #
+        # Once all the atuomatic binary builds have completed, the HTML comments
+        # in the text below will be removed to reveal the download links.
         message = dedent(
             """\
-LLVM {release} Release
+## LLVM {release} Release
+
+<!-- DOWNLOAD_LINKS_BEGIN
+**Linux:**
+* [x86_64](https://github.com/llvm/llvm-project/releases/download/llvmorg-{release}/LLVM-{release}-Linux-X64.tar.xz) ([signature](https://github.com/llvm/llvm-project/releases/download/llvmorg-{release}/LLVM-{release}-Linux-X64.tar.xz.jsonl))
+* [Arm64](https://github.com/llvm/llvm-project/releases/download/llvmorg-{release}/LLVM-{release}-Linux-ARM64.tar.xz) ([signature](https://github.com/llvm/llvm-project/releases/download/llvmorg-{release}/LLVM-{release}-Linux-ARM64.tar.xz.jsonl))
+
+**macOS:**
+* [Apple Silicon](https://github.com/llvm/llvm-project/releases/download/llvmorg-{release}/LLVM-{release}-macOS-ARM64.tar.xz) (ARM64) ([signature](https://github.com/llvm/llvm-project/releases/download/llvmorg-{release}/LLVM-{release}-macOS-ARM64.tar.xz.jsonl))
+* [Intel](https://github.com/llvm/llvm-project/releases/download/llvmorg-{release}/LLVM-{release}-macOS-X64.tar.xz) (x86-64) ([signature](https://github.com/llvm/llvm-project/releases/download/llvmorg-{release}/LLVM-{release}-macOS-X64.tar.xz.jsonl))
+DOWNLOAD_LINKS_END -->
+
+Download links for Linux and macOS will appear here when all the builds have completed. <!-- DOWNLOAD_LINKS_PLACEHOLDER -->
+
+For Windows, and any other variants of platform and architecture, check the full list of release packages at the bottom of this release page.
----------------
DavidSpickett wrote:

I'll add the links and you can see what you think.

https://github.com/llvm/llvm-project/pull/147719