Winch: Clean up Wast SIMD tests (#10203)

* Winch: Clean up Wast SIMD tests

* Add _simd_load.wast to unsupported if no AVX

Author: jeffcharles

crates/wast-util/src/lib.rs

@@ -466,6 +466,7 @@ impl WastTest {
                     "misc_testsuite/simd/replace-lane-preserve.wast",
                     "misc_testsuite/simd/spillslot-size-fuzzbug.wast",
                     "misc_testsuite/winch/_simd_lane.wast",
+                    "misc_testsuite/winch/_simd_load.wast",
                     "misc_testsuite/winch/_simd_splat.wast",
                     "spec_testsuite/simd_align.wast",
                     "spec_testsuite/simd_conversions.wast",