Add const tests for sse4.2

Author: sayantn

crates/core_arch/src/x86/sse42.rs

@@ -610,6 +610,7 @@ unsafe extern "C" {
 
 #[cfg(test)]
 mod tests {
+    use crate::core_arch::assert_eq_const as assert_eq;
     use stdarch_test::simd_test;
 
     use crate::core_arch::x86::*;
@@ -790,7 +791,7 @@ mod tests {
     }
 
     #[simd_test(enable = "sse4.2")]
-    unsafe fn test_mm_cmpgt_epi64() {
+    const unsafe fn test_mm_cmpgt_epi64() {
         let a = _mm_setr_epi64x(0, 0x2a);
         let b = _mm_set1_epi64x(0x00);
         let i = _mm_cmpgt_epi64(a, b);