Add create & delete array tests for yul

test/libsolidity/semanticTests/array/delete_memory_array.sol

@@ -0,0 +1,17 @@
+contract C {
+
+    function len() public returns (uint ret) {
+        uint[] memory data = new uint[](2);
+        data[0] = 234;
+        data[1] = 123;
+        delete data;
+        assembly {
+            ret := mload(data)
+        }
+    }
+}
+
+// ====
+// compileViaYul: also
+// ----
+// len() -> 0