Building with clang fails due to 'const' attribute on function returning 'void' for version 9.5

[FragmentedCurve]

When compiling libj version 9.5 with clang using the command CC=clang ./build_libj.sh, yields the following errors:

In file included from ../../../../jsrc/viavx5.c:6:
In file included from ../../../../jsrc/j.h:229:
../../../../jsrc/../sleef/include/sleefquad.h:259:31: error: 'const' attribute on function returning 'void'; attribute ignored [-Werror,-Wignored-attributes]
  259 | SLEEF_IMPORT SLEEF_CONST void Sleef_storeq2_sse2(Sleef_quad *, Sleef_quadx2);
      |                               ^
../../../../jsrc/../sleef/include/sleefquad.h:328:31: error: 'const' attribute on function returning 'void'; attribute ignored [-Werror,-Wignored-attributes]
  328 | SLEEF_IMPORT SLEEF_CONST void Sleef_storeq2_avx2128(Sleef_quad *, Sleef_quadx2);
      |                               ^
../../../../jsrc/../sleef/include/sleefquad.h:397:31: error: 'const' attribute on function returning 'void'; attribute ignored [-Werror,-Wignored-attributes]

I've truncated the output. To build successfully, I have to run CC=clang CFLAGS=" -Wno-ignored-attributes" ./build_libj.sh.

This bug does not exist in the master branch, only 9.5.

[bilam]

compilation was successful with the version of gcc at that time. I don't feel the need to retrofit unless there is a maintenance release of 9.5

[moon-chilled]

i think this is a sleef bug; __attribute__((const)) should not be applied to those functions