7zip reader: add SPARC filter support for non-LZMA compressors (#2399)

7zip reader: add SPARC filter support for non-LZMA compressors (#2399)

These two new test archives contain a C hello world executable built
like so on a ubuntu 24.04 machine:

```
#include <stdio.h>

int main(int argc, char *argv[]) {
  printf("hello, world\n");
  return 0;
}
```

`sparc64-linux-gnu-gcc hw.c -o hw-sparc64 -Wall`

The two test archives that contain this executable were created like so,
using the https://github.com/tehmul/p7zip-zstd fork of 7-Zip:
`7z a -t7z -m0=zstd -mf=SPARC
libarchive/test/test_read_format_7zip_zstd_sparc.7z hw-sparc64`
`7z a -t7z -m0=lzma2 -mf=SPARC
libarchive/test/test_read_format_7zip_lzma2_sparc.7z hw-sparc64`

Two test files are required, because the 7zip reader code has two
different paths, one for lzma and one for all other compressors.

The test_read_format_7zip_lzma2_sparc test is expected to pass, because
LZMA BCJ filters are implemented in liblzma.

The test_read_format_7zip_zstd_sparc test is expected to fail in the
first commit, because libarchive does not currently implement the SPARC
BCJ filter. The second commit will make test_read_format_7zip_zstd_sparc
pass.