Change the I64xLeS instruction encoding (#811)

Change the u32 field of the I64x2LeS instruction from 0xDD to 0xDA to
match the spec.

crates/wasm-encoder/src/core/code.rs

@@ -2331,7 +2331,7 @@ impl Encode for Instruction<'_> {
             }
             Instruction::I64x2LeS => {
                 sink.push(0xFD);
-                0xDDu32.encode(sink);
+                0xDAu32.encode(sink);
             }
             Instruction::I64x2GeS => {
                 sink.push(0xFD);