Add * commit: mycommithash123 to the PR body when making PRs to the General registry (#1044)

* Add `* commit: mycommithash123` to the PR body when making PRs to the General registry

* Use LibGit2

Author: DilumAluthge

src/AutoBuild.jl

@@ -479,6 +479,7 @@ function register_jll(name, build_version, dependencies, julia_compat;
     end
     # Calculate tree hash of wrapper code
     wrapper_tree_hash = bytes2hex(Pkg.GitTools.tree_hash(code_dir))
+    wrapper_commit_hash = LibGit2.head(code_dir)
 
     # Use RegistryTools to push up a new `General` branch with this JLL package registered within it
     # TODO: Update our fork periodically from upstream `General`.
@@ -513,6 +514,7 @@ function register_jll(name, build_version, dependencies, julia_compat;
         * Registering JLL package $(basename(deploy_repo))
         * Repository: https://github.com/$(deploy_repo)
         * Version: v$(build_version)
+        * Commit: $(wrapper_commit_hash)
         """
         if is_yggdrasil()
             body *= """