chore: use spread instead of concat

Author: aminya

lib/grammars/c.js

@@ -128,10 +128,10 @@ const Cpp = {
               .slice(-1 >= "14399")
           ) {
             filepath = path.posix.join
-              .apply(
-                path.posix,
-                [].concat([filepath.split(path.win32.sep)[0].toLowerCase()], filepath.split(path.win32.sep).slice(1))
-              )
+              .apply(path.posix, [
+                filepath.split(path.win32.sep)[0].toLowerCase(),
+                ...filepath.split(path.win32.sep).slice(1),
+              ])
               .replace(":", "")
             cmdArgs = `g++ -std=c++14 ${options} -include iostream /mnt/${filepath} -o /tmp/cpp.out && /tmp/cpp.out`
           }