One of my AArch64 CIs fails to build with an obscure message like:

```

=== Output from failing command(s) repeated here ===
* For target support_native_jdk.incubator.vector_libsleef_vector_math_sve.o:
{standard input}: Assembler messages:
{standard input}:9: Error: unknown pseudo-op: `.variant_pcs'
{standard input}:1585: Error: unknown pseudo-op: `.variant_pcs'
{standard input}:3123: Error: unknown pseudo-op: `.variant_pcs'
{standard input}:4216: Error: unknown pseudo-op: `.variant_pcs'
{standard input}:5908: Error: unknown pseudo-op: `.variant_pcs'
{standard input}:7033: Error: unknown pseudo-op: `.variant_pcs'
{standard input}:7682: Error: unknown pseudo-op: `.variant_pcs'
{standard input}:8559: Error: unknown pseudo-op: `.variant_pcs'
{standard input}:9481: Error: unknown pseudo-op: `.variant_pcs'
{standard input}:10621: Error: unknown pseudo-op: `.variant_pcs'
{standard input}:11269: Error: unknown pseudo-op: `.variant_pcs'
{standard input}:11988: Error: unknown pseudo-op: `.variant_pcs'
{standard input}:12622: Error: unknown pseudo-op: `.variant_pcs'
{standard input}:12934: Error: unknown pseudo-op: `.variant_pcs'
   ... (rest of output omitted)

```

I suspect it is caused by JDK-8312425 integration. I further suspect this is caused by binutils in that toolchain being too old. In this particular one, binutils is at 2.29.1. I'll try to upgrade the build toolchain. The CI in question uses a crosstool-ng built toolchain:

Tools summary:
* Toolchain: gcc (GNU Compiler Collection)
* Sysroot: /home/buildbot/deps/x-tools/aarch64-linux-gnu/aarch64-linux-gnu/sysroot
* C Compiler: Version 12.4.0 (at /home/buildbot/deps/x-tools/aarch64-linux-gnu/bin/aarch64-linux-gnu-gcc)
* C++ Compiler: Version 12.4.0 (at /home/buildbot/deps/x-tools/aarch64-linux-gnu/bin/aarch64-linux-gnu-g++)

It looks like feature auto-detection did not reliably verified we are able to build and assemble libsleef.