implement getArch for LintingFile type

Fixes the overcaching of files for different arches in jshint

packages/jshint/plugin/lint-jshint.js

@@ -56,7 +56,9 @@ JsHintLinter.prototype.processFilesForTarget = function (files, globals) {
       return;
 
     // skip files we already linted
-    var hashKey = file.getPackageName() + '/' + file.getPathInPackage();
+    var hashKey = JSON.stringify([
+      file.getPackageName(), file.getPathInPackage(), file.getArch()]);
+
     if (self.hashDict[hashKey] === file.getSourceHash())
       return;
     self.hashDict[hashKey] = file.getSourceHash();

tools/build-plugin.js

@@ -79,6 +79,16 @@ _.extend(exports.InputFile.prototype, {
   getSourceHash: function () {
     throw new Error("Not Implemented");
   },
+  /**
+   * @summary Returns a string symbol representing the architecture that is
+   * targetted by processing this file. Can be used to implement caching.
+   * XXX BBP is this doc string good?
+   * @memberof InputFile
+   * @returns {String}
+   */
+  getArch: function () {
+    throw new Error("Not Implemented");
+  },
 
   /**
    * @summary Returns the full contents of the file as a string.

tools/compiler.js

@@ -251,7 +251,8 @@ var lintUnibuild = function (options) {
       relPath: relPath,
       contents: contents,
       'package': isopack.name,
-      hash: hash
+      hash: hash,
+      arch: inputSourceArch.arch
     };
   });
 

tools/linter-plugin.js

@@ -29,6 +29,9 @@ _.extend(LintingFile.prototype, {
   },
   getSourceHash: function () {
     return this._source.hash;
+  },
+  getArch: function () {
+    return this._source.arch;
   }
 });