test: skip long path tests on non-Windows

If not running on Windows it skips the long path tests in:
* test-fs-long-path.js
* test-require-long-path.js
Fixes: #2255
PR-URL: #4116
Reviewed-By: Ben Noordhuis <info@bnoordhuis.nl>
Reviewed-By: James M Snell <jasnell@gmail.com>
Reviewed-By: Minwoo Jung <jmwsoft@gmail.com>

Author: rsp

test/parallel/test-fs-long-path.js

@@ -4,6 +4,11 @@ var fs = require('fs');
 varpath=require('path');
 varassert=require('assert');
 
+if(!common.isWindows){
+console.log('1..0 # Skipped: this test is Windows-specific.');
+return;
+}
+
 varsuccesses=0;
 
 // make a path that will be at least 260 chars long.

test/parallel/test-require-long-path.js

@@ -3,6 +3,11 @@ const common = require('../common');
 constfs=require('fs');
 constpath=require('path');
 
+if(!common.isWindows){
+console.log('1..0 # Skipped: this test is Windows-specific.');
+return;
+}
+
 // make a path that is more than 260 chars long.
 constdirNameLen=Math.max(260-common.tmpDir.length,1);
 constdirName=path.join(common.tmpDir,'x'.repeat(dirNameLen));