mark LZCNT intrinsics as safe

Mark all LZCNT intrinsics as safe.

Author: usamoi

crates/core_arch/src/x86/abm.rs

@@ -29,7 +29,7 @@ use stdarch_test::assert_instr;
 #[target_feature(enable = "lzcnt")]
 #[cfg_attr(test, assert_instr(lzcnt))]
 #[stable(feature = "simd_x86", since = "1.27.0")]
-pub unsafe fn _lzcnt_u32(x: u32) -> u32 {
+pub fn _lzcnt_u32(x: u32) -> u32 {
     x.leading_zeros()
 }
 

crates/core_arch/src/x86_64/abm.rs

@@ -29,7 +29,7 @@ use stdarch_test::assert_instr;
 #[target_feature(enable = "lzcnt")]
 #[cfg_attr(test, assert_instr(lzcnt))]
 #[stable(feature = "simd_x86", since = "1.27.0")]
-pub unsafe fn _lzcnt_u64(x: u64) -> u64 {
+pub fn _lzcnt_u64(x: u64) -> u64 {
     x.leading_zeros() as u64
 }