RFR: 8253253: Binutils tar ball extension update to gz

[Junyuan Zheng]

On Wed, 16 Sep 2020 17:20:18 GMT, Erik Joelsson <erikj at openjdk.org> wrote:

>> Our infra team found this error when building DevKit with GCC 4.9.2. The binutils version is 2.25, and an *.xz doesn't
>> exist on https://ftp.gnu.org/pub/gnu/binutils.  Hence, we would like to submit a PR to update *.xz to *.gz.
>> We have confirmed that *.gz exists for all binutil version.
>
> Marked as reviewed by erikj (Reviewer).

We only use the GCC 4.9.2 for jdk8u. The openjdk/jdk repository's devkit contains all devkits that support older jdk.
So we can just use this file to build all the devkits instead of pulling devkits from jdk8u and jdk11u. I also notice
newer code always contains devkit from older code. jdk contains (gcc 9, 7, 8 4), jdk11u contains (gcc 7, 4), and jdk8u
contains (gcc 4). But I will abandon this PR and change our workflow if outdated devkit will be eventually removed from
openjdk/jdk repository.

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PR: https://git.openjdk.java.net/jdk/pull/162