tr: add spell-checker ignore for AVX2 intrinsic names

The intrinsics blendv, cmpgt, loadu, and storeu introduced in the AVX2
range translation kernel are flagged by cspell. Annotate the file so the
style/spelling CI job stays green.

Author: jeffhuang

src/uu/tr/src/simd.rs

@@ -3,6 +3,8 @@
 // For the full copyright and license information, please view the LICENSE
 // file that was distributed with this source code.
 
+// spell-checker:ignore (intrinsics) blendv cmpgt loadu storeu
+
 //! I/O processing infrastructure for tr operations with SIMD optimizations
 
 use crate::operation::{AsciiRangeTranslate, ChunkProcessor};