[clang] [llvm] [CodeGen][KCFI] Allow setting type hash from xxHash64 to FNV-1a (PR #167254)

[Nathan Chancellor via cfe-commits]

nathanchance wrote:

This breaks `ARCH=arm64 allmodconfig`:

```
$ make -skj"$(nproc)" ARCH=arm64 LLVM=1 clean allmodconfig ipc/ipc_sysctl.o
<inline asm>:6:55: error: expected newline
    6 | .set __kcfi_typeid_proc_doulongvec_minmax, 3439065979 # -855901317
      |                                                       ^
<inline asm>:8:53: error: expected newline
    8 | .set __kcfi_typeid_proc_dointvec_minmax, 3439065979 # -855901317
      |                                                     ^
2 errors generated.
make[5]: *** [scripts/Makefile.build:287: ipc/ipc_sysctl.o] Error 1
...

https://github.com/llvm/llvm-project/pull/167254