git: openjdk/jdk18: 8279702: [macosx] ignore xcodebuild warnings on M1

[Christoph Langer]

Changeset: 4b520f00
Author:    Johannes Bechberger <johannes.bechberger at sap.com>
Committer: Christoph Langer <clanger at openjdk.org>
Date:      2022-01-14 13:53:53 +0000
URL:       https://git.openjdk.java.net/jdk18/commit/4b520f0001be5f33996d5ab7d9ad75773a847e54

8279702: [macosx] ignore xcodebuild warnings on M1

Reviewed-by: goetz, erikj

! make/autoconf/toolchain.m4