Compile problems w/gcc 9.4.0 in linux-next

[Michael Kelley]

Brian/Ingo/Ard -

I'm seeing a compile problem in linux-next-20250319 with gcc 9.4.0. I've bisected
to a group of 6 commits that you authored:

a9a76b38aaf5 x86/boot: Disable stack protector for early boot code
f58b63857ae3 x86/pvh: Use fixed_percpu_data for early boot GSBASE
cb7927fda002 x86/relocs: Handle R_X86_64_REX_GOTPCRELX relocations
78c4374ef8b8 x86/module: Deal with GOT based stack cookie load on Clang < 17
80d47defddc0 x86/stackprotector/64: Convert to normal per-CPU variable
9d7de2aa8b41 x86/percpu/64: Use relative percpu offsets

As of a9a76b38aaf5, everything compiles correctly.

For f58b63857ae3 thru 80d47defddc0, this error occurs:

    arch/x86/platform/pvh/head.S: Assembler messages:
    arch/x86/platform/pvh/head.S:183: Error: operand size mismatch for `movq'

As of 9d7de2aa8b41 and later, the head.S error goes away, and this
error occurs:

    lib/zstd/compress/huf_compress.c:1033:1: internal compiler error: Segmentation fault
     1033 | {
          | ^
    Please submit a full bug report,
    with preprocessed source if appropriate.
    See <file:///usr/share/doc/gcc-9/README.Bugs> for instructions.

Interestingly, if DYNAMIC_BMI2 in lib/zstd/common/portability_macros.h
is changed on line 61 to always be defined as 0, the compile problem in
huf_compress.c goes away.

I'm using gcc 9.4.0 in an Ubuntu 20.04 install as it's the standard compiler 
for that version of Ubuntu. I'm guessing that getting a fix for that
relatively old version of gcc isn't likely. I have not tested with other
gcc versions.

Thoughts on how to proceed? 

Michael Kelley