Bug#1049362: clang SIMD compatibility headers broken on ppc64el

[Timothy Pearson]

Package: libclang-common-15-dev
Version: 1:15.0.7-8
Severity: important
Tags: upstream
Forwarded: https://github.com/llvm/llvm-project/issues/64664

After upgrading from clang 14 to clang 15 debian's chromium package fails to compile with SIMD errors:

/usr/lib/llvm-15/lib/clang/15.0.7/include/ppc_wrappers/smmintrin.h:71:25: error: use of undeclared identifier '__builtin_mffs'
    __fpscr_save.__fr = __builtin_mffs();
                        ^
/usr/lib/llvm-15/lib/clang/15.0.7/include/ppc_wrappers/smmintrin.h:74:5: error: use of undeclared identifier '__builtin_mtfsf'
    __builtin_mtfsf(0b00000011, __fpscr_save.__fr);
    ^
/usr/lib/llvm-15/lib/clang/15.0.7/include/ppc_wrappers/smmintrin.h:86:25: error: use of undeclared identifier '__builtin_mffsl'; did you mean '__builtin_infl'?
    __fpscr_save.__fr = __builtin_mffsl();
                        ^
/usr/lib/llvm-15/lib/clang/15.0.7/include/ppc_wrappers/smmintrin.h:86:25: note: '__builtin_infl' declared here
/usr/lib/llvm-15/lib/clang/15.0.7/include/ppc_wrappers/smmintrin.h:89:5: error: use of undeclared identifier '__builtin_set_fpscr_rn'
    __builtin_set_fpscr_rn(0b00);
    ^
/usr/lib/llvm-15/lib/clang/15.0.7/include/ppc_wrappers/smmintrin.h:105:5: error: use of undeclared identifier '__builtin_set_fpscr_rn'
    __builtin_set_fpscr_rn(__fpscr_save.__fpscr);
    ^
/usr/lib/llvm-15/lib/clang/15.0.7/include/ppc_wrappers/smmintrin.h:131:25: error: use of undeclared identifier '__builtin_mffsl'; did you mean '__builtin_infl'?
    __fpscr_save.__fr = __builtin_mffsl();
                        ^
/usr/lib/llvm-15/lib/clang/15.0.7/include/ppc_wrappers/smmintrin.h:86:25: note: '__builtin_infl' declared here
    __fpscr_save.__fr = __builtin_mffsl();
                        ^
/usr/lib/llvm-15/lib/clang/15.0.7/include/ppc_wrappers/smmintrin.h:133:5: error: use of undeclared identifier '__builtin_mtfsf'
    __builtin_mtfsf(0b00000011, __fpscr_save.__fr);
    ^
/usr/lib/llvm-15/lib/clang/15.0.7/include/ppc_wrappers/smmintrin.h:162:25: error: use of undeclared identifier '__builtin_mffs'
    __fpscr_save.__fr = __builtin_mffs();
                        ^
/usr/lib/llvm-15/lib/clang/15.0.7/include/ppc_wrappers/smmintrin.h:165:5: error: use of undeclared identifier '__builtin_mtfsf'
    __builtin_mtfsf(0b00000011, __fpscr_save.__fr);
    ^
/usr/lib/llvm-15/lib/clang/15.0.7/include/ppc_wrappers/smmintrin.h:177:25: error: use of undeclared identifier '__builtin_mffsl'; did you mean '__builtin_infl'?
    __fpscr_save.__fr = __builtin_mffsl();
                        ^
/usr/lib/llvm-15/lib/clang/15.0.7/include/ppc_wrappers/smmintrin.h:86:25: note: '__builtin_infl' declared here
    __fpscr_save.__fr = __builtin_mffsl();
                        ^
/usr/lib/llvm-15/lib/clang/15.0.7/include/ppc_wrappers/smmintrin.h:180:5: error: use of undeclared identifier '__builtin_set_fpscr_rn'
    __builtin_set_fpscr_rn(0b00);
    ^
/usr/lib/llvm-15/lib/clang/15.0.7/include/ppc_wrappers/smmintrin.h:196:5: error: use of undeclared identifier '__builtin_set_fpscr_rn'
    __builtin_set_fpscr_rn(__fpscr_save.__fpscr);
    ^
/usr/lib/llvm-15/lib/clang/15.0.7/include/ppc_wrappers/smmintrin.h:222:25: error: use of undeclared identifier '__builtin_mffsl'; did you mean '__builtin_infl'?
    __fpscr_save.__fr = __builtin_mffsl();
                        ^
/usr/lib/llvm-15/lib/clang/15.0.7/include/ppc_wrappers/smmintrin.h:86:25: note: '__builtin_infl' declared here
    __fpscr_save.__fr = __builtin_mffsl();
                        ^
/usr/lib/llvm-15/lib/clang/15.0.7/include/ppc_wrappers/smmintrin.h:224:5: error: use of undeclared identifier '__builtin_mtfsf'
    __builtin_mtfsf(0b00000011, __fpscr_save.__fr);

This is a bug in Clang, and is being tracked upstream at https://github.com/llvm/llvm-project/issues/64664