Replace libffi/aarch64 with the latest version in GitHub

[ChengJin01]

The changes aim to resolve the libffi related issue detected on jtreg FFI downcall & upcall
tests suites by replacing the outdated version on Aarch64 with the latest version in Github at
https://github.com/libffi/libffi/tree/master/src/aarch64 to better support the downcall & upcall
with struct in JEP389/424(Foreign Linker API) which is part of the Panama project.

The latest committed SHA: c6dc125afba294b9b9613392c492ae18df3ede84

Signed-off-by: ChengJin01 jincheng@ca.ibm.com

[ChengJin01]

Note:

1. The changes(verified in internal builds & external builds) resolves the libffi specific issue detected in FFI Jtreg tests
   in downcall (e.g.https://github.com/ibmruntimes/openj9-openjdk-jdk19/blob/openj9/test/jdk/java/foreign/TestDowncallStack.java) to deal with the cases of complex combination of struct arguments in native via libffi.
2. The changes mainly copy the latest code in libffi/aarch64 from github without modification (in which case no copyright is required) while the rest of files are partially updated with the latest code specific to Aarch64 so as to adapt to the existing settings in OpenJ9.

Reviewer: @pshipton, @gacholio
FYI: @tajila, @DanHeidinga, @dnakamura, @knn-k

[ChengJin01]

The following files are directly copied from https://github.com/libffi/libffi/tree/master/src/aarch64 and https://github.com/libffi/libffi/blob/master/src/tramp.c:

runtime/libffi/aarch64/ffi.c
runtime/libffi/aarch64/ffitarget.h
runtime/libffi/aarch64/internal.h
runtime/libffi/aarch64/sysv.S
runtime/libffi/tramp.c

plus our own setting with updated code specific to Aarch64.

runtime/libffi/preconf/xr64/fficonfig.h

So the copyright & line endings check at https://openj9-jenkins.osuosl.org/job/PullRequest-CopyrightCheck-OpenJ9/6979/console and https://openj9-jenkins.osuosl.org/job/PullRequest-LineEndingsCheck-OpenJ9/6966/console are not required in such case.

[pshipton]

The changes aren't all specific to aarch64, did you test all the platforms?

[ChengJin01]

The changes aren't all specific to aarch64, did you test all the platforms?

Yes, they were verified on all platforms.

[pshipton]

Which Java versions were tested?

[ChengJin01]

Which Java versions were tested?

Internal builds: Java8
External builds: Java11, 17 & 19.

[pshipton]

I assume internal means IBM Java 8? You'd better try OpenJ9 Java 8 as well, just in case. Some of the compiler levels are different.

[ChengJin01]

I assume internal means IBM Java 8?

Yes. It's IBM Java 8.

You'd better try OpenJ9 Java 8 as well, just in case. Some of the compiler levels are different.

Will launch personal builds to double-check.

[ChengJin01]

External personal builds (OpenJ9 Java 8) on all supported platforms passed without libffi related issue.

[pshipton]

jenkins test sanity xmac jdk8