Subject: bug#55455: [macOS] Fix build when using brew's libgccjit

From: John Buckley <[email-masked]>
Date: Mon, 16 May 2022 17:11:31 +0100

A little more info:

- This patch will not currently work on ARM64 because brew's libgccjit is
using a fork for ARM. The .so -> .dylib fix for macOS has not been
incorporated into the fork yet.
- I forgot to add the [PATCH] prefix to this issue. Apologies.

For more context please see:
https://github.com/Homebrew/homebrew-core/issues/101673