[Sol->Yul] Implement .length for storage arrays

test/libsolidity/semanticTests/viaYul/array_storage_length_access.sol

@@ -0,0 +1,19 @@
+contract C {
+	uint[] storageArray;
+	function set_get_length(uint256 len) public returns (uint256)
+	{
+		storageArray.length = len;
+		return storageArray.length;
+	}
+
+}
+// ====
+// compileViaYul: true
+// ----
+// set_get_length(uint256): 0 -> 0
+// set_get_length(uint256): 1 -> 1
+// set_get_length(uint256): 10 -> 10
+// set_get_length(uint256): 20 -> 20
+// set_get_length(uint256): 0 -> 0
+// set_get_length(uint256): 0xFF -> 0xFF
+// set_get_length(uint256): 0xFFFF -> 0xFFFF