fix: Ensure prepared externals binaries are executable

It's what npm ensures, hence npm-cross-link should also

lib/private/setup-dependency/install-external/prepare/index.js

@@ -1,16 +1,18 @@
 "use strict";
 
-const memoizee          = require("memoizee")
-    , { resolve }       = require("path")
-    , isDirectory       = require("fs2/is-directory")
-    , mkdir             = require("fs2/mkdir")
-    , rename            = require("fs2/rename")
-    , rm                = require("fs2/rm")
-    , tmpdir            = require("os").tmpdir()
-    , log               = require("log").get("npm-cross-link")
-    , cachePath         = require("../../../cache").path
-    , getPackageJson    = require("../../../../get-package-json")
-    , updatePackageJson = require("../../../update-package-json");
+const memoizee            = require("memoizee")
+    , { resolve }         = require("path")
+    , isDirectory         = require("fs2/is-directory")
+    , mkdir               = require("fs2/mkdir")
+    , rename              = require("fs2/rename")
+    , chmod               = require("fs2/chmod")
+    , rm                  = require("fs2/rm")
+    , tmpdir              = require("os").tmpdir()
+    , log                 = require("log").get("npm-cross-link")
+    , cachePath           = require("../../../cache").path
+    , getPackageJson      = require("../../../../get-package-json")
+    , updatePackageJson   = require("../../../update-package-json")
+    , resolveBinariesDict = require("../resolve-binaries-dict");
 
 const methods = [require("./sem-ver"), require("./git"), require("./other")];
 
@@ -38,6 +40,17 @@ module.exports = memoizee(
 			recursive: true,
 			force: true
 		});
+
+		if (process.plaftorm !== "win32") {
+			const binariesDict = resolveBinariesDict(packageTmpDir);
+			if (binariesDict) {
+				await Promise.all(
+					Object.values(binariesDict).map(path =>
+						chmod(resolve(packageTmpDir, path), 0o111, { append: true })
+					)
+				);
+			}
+		}
 		if (!versionCachePath) return packageTmpDir;
 
 		await rename(packageTmpDir, versionCachePath, { intermediate: true });

package.json

@@ -16,7 +16,7 @@
 		"es5-ext": "^0.10.50",
 		"essentials": "^1.0.0",
 		"event-emitter": "^0.3.5",
-		"fs2": "^0.3.4",
+		"fs2": "^0.3.5",
 		"got": "^9.6.0",
 		"log": "^6.0.0",
 		"log-node": "^7.0.0",