RFR: 8304006: jlink should create the jimage file in the native endian for the target platform [v10]

[Jaikiran Pai]

On Tue, 21 Mar 2023 18:55:17 GMT, Mandy Chung <mchung at openjdk.org> wrote:

>> src/jdk.jlink/share/classes/jdk/tools/jlink/internal/Platform.java line 192:
>> 
>>> 190:             case "s390x"           -> Architecture.s390x;
>>> 191:             case "sparc"           -> Architecture.SPARC;
>>> 192:             case "sparcv9"         -> Architecture.SPARCv9;
>> 
>> This list should be trimmed to the ones supported in the mainline as in `target.properties`.
>
> Also `is64Bit` will need update for other 64-bit platforms.

I've now updated the PR to trim down the target platforms to match what we have in `target.properties`. Additionally, `is64Bit` has been enhanced too.

I would like to note that, in an intermediate version of this PR, I made `is64Bit` return true for `arm` architecture. I did so because from the materials I found, ARM supports both 32 bit and 64 bit architectures, but the recent versions are 64 bit. So I thought it would be appropriate to consider it 64 bit.

However, I then looked up the `platform.m4` build file and it marks `arm` architecture as 32 bit https://github.com/openjdk/jdk/blob/master/make/autoconf/platform.m4#L57. So I've updated the PR to return false from `is64Bit` from `arm` arch.

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PR Review Comment: https://git.openjdk.org/jdk/pull/11943#discussion_r1145582050