neon/cvt: don't use vec_ctsl on POWER
GCC is okay with it, but clang isn't.  On z/Arch it's deprecated in
favor of vec_signed.
Fixes
@@ -293,8 +293,8 @@ simde_vcvtq_s64_f64(simde_float64x2_t a) {
return vcvtq_s64_f64(a);
#elif defined(SIMDE_X86_AVX512VL_NATIVE) && defined(SIMDE_X86_AVX512DQ_NATIVE)
return _mm_cvtpd_epi64(_mm_round_pd(a, _MM_FROUND_TO_ZERO));
- #elif defined(SIMDE_POWER_ALTIVEC_P8_NATIVE) || defined(SIMDE_ZARCH_ZVECTOR_13_NATIVE)
- return vec_ctsl(a, 0);
+ #elif defined(SIMDE_ZARCH_ZVECTOR_13_NATIVE)
+ return vec_signed(a);
#else
simde_float64x2_private a_ = simde_float64x2_to_private(a);
simde_int64x2_private r_;
