test: enforce strict mode in test-zlib-const

Instead of checking that assignments fail silently in sloppy mode, check
that they throw in strict mode.

Author: Trott

test/parallel/test-zlib-const.js

@@ -1,4 +1,4 @@
-/* eslint-disable strict */
+'use strict';
 require('../common');
 const assert = require('assert');
 
@@ -9,27 +9,17 @@ assert.strictEqual(zlib.constants.Z_OK, 0,
                      'Expected Z_OK to be 0;',
                      `got ${zlib.constants.Z_OK}`,
                    ].join(' '));
-zlib.constants.Z_OK = 1;
-assert.strictEqual(zlib.constants.Z_OK, 0,
-                   [
-                     'Z_OK should be immutable.',
-                     `Expected to get 0, got ${zlib.constants.Z_OK}`,
-                   ].join(' '));
+
+assert.throws(() => { zlib.constants.Z_OK = 1; },
+              TypeError, 'zlib.constants.Z_OK should be immutable');
 
 assert.strictEqual(zlib.codes.Z_OK, 0,
                    `Expected Z_OK to be 0; got ${zlib.codes.Z_OK}`);
-zlib.codes.Z_OK = 1;
-assert.strictEqual(zlib.codes.Z_OK, 0,
-                   [
-                     'Z_OK should be immutable.',
-                     `Expected to get 0, got ${zlib.codes.Z_OK}`,
-                   ].join(' '));
-zlib.codes = { Z_OK: 1 };
-assert.strictEqual(zlib.codes.Z_OK, 0,
-                   [
-                     'Z_OK should be immutable.',
-                     `Expected to get 0, got ${zlib.codes.Z_OK}`,
-                   ].join(' '));
+assert.throws(() => { zlib.codes.Z_OK = 1; },
+              TypeError, 'zlib.codes.Z_OK should be immutable');
+
+assert.throws(() => { zlib.codes = { Z_OK: 1 }; },
+              TypeError, 'zlib.codes should be immutable');
 
 assert.ok(Object.isFrozen(zlib.codes),
           [