[machinst x64]: enable lane spec tests

build.rs

@@ -196,6 +196,8 @@ fn experimental_x64_should_panic(testsuite: &str, testname: &str, strategy: &str
         ("simd", "simd_f32x4_cmp") => return false,
         ("simd", "simd_f64x2_arith") => return false,
         ("simd", "simd_f64x2_cmp") => return false,
+        ("simd", "simd_lane") => return false,
+        ("simd", "simd_load_splat") => return false,
         ("simd", "simd_store") => return false,
         ("simd", _) => return true,
         _ => {}