RFR: 8340804: doc/building.md update Xcode instructions to note that full install is required [v3]

[duke]

On Tue, 24 Sep 2024 17:18:57 GMT, George Adams <gdams at openjdk.org> wrote:

>> Since JDK17 there has been a dependency on metal in the macOS builds which is only available as part of the full Xcode IDE (rather than command-line tools). We currently recommend only installing the command-line tools in the building.md doc which is incorrect.
>> 
>> See https://github.com/openjdk/jdk/blob/e1c4d3039f6b5106ce3f65d50f607eacc2a8d168/make/autoconf/toolchain.m4#L681
>
> George Adams has updated the pull request incrementally with one additional commit since the last revision:
> 
>   Update building.md
>   
>   Co-authored-by: Erik Joelsson <37597443+erikj79 at users.noreply.github.com>

@gdams 
Your change (at version 32dd4677ceff7e9fd626fb8561b49a15cab5beb1) is now ready to be sponsored by a Committer.

-------------

PR Comment: https://git.openjdk.org/jdk/pull/21154#issuecomment-2372059685