fix: remove inline(always) from target_feature functions

Rust stable doesn't allow combining #[inline(always)] with
#[target_feature] - this is an unstable feature (rust-lang/rust#145574).

Author: mrecachinas

src/lib.rs

@@ -308,7 +308,6 @@ mod x86_simd {
     use std::arch::x86_64::*;
 
     /// SSE4.1 popcount for 128-bit value using hardware popcnt
-    #[inline(always)]
     #[target_feature(enable = "sse4.1", enable = "popcnt")]
     pub unsafe fn popcnt128_sse(n: __m128i) -> u64 {
         let lo = _mm_cvtsi128_si64(n) as u64;
@@ -318,7 +317,6 @@ mod x86_simd {
 
     /// SSE4.1 VPSHUFB-based popcount (accumulates into byte lanes)
     /// Returns vector with per-byte popcounts - use _mm_sad_epu8 to sum
-    #[inline(always)]
     #[target_feature(enable = "ssse3")]
     unsafe fn popcnt128_shuffle(v: __m128i, mask: __m128i, table: __m128i) -> __m128i {
         let lo = _mm_and_si128(v, mask);
@@ -420,7 +418,6 @@ mod x86_simd {
     }
 
     /// AVX2 VPSHUFB-based popcount - accumulates into byte lanes
-    #[inline(always)]
     #[target_feature(enable = "avx2")]
     unsafe fn popcnt256_shuffle(v: __m256i, mask: __m256i, table: __m256i) -> __m256i {
         let lo = _mm256_and_si256(v, mask);