Update crates/stdarch-gen/neon.spec

Co-Authored-By: bjorn3 <bjorn3@users.noreply.github.com>

Author: Licenser

crates/stdarch-gen/neon.spec

@@ -1,6 +1,6 @@
 // ARM Neon intrinsic specification.
 // 
-// This file contains the sepcification for a number of 
+// This file contains the specification for a number of 
 // intrinsics that allows us to generate them along with
 // their test cases.
 //