Fixed specifying annotation processors path in javac front-end.

	Change on 2016/12/23 by tball <tball@google.com>

-------------
Created by MOE: https://github.com/google/moe
MOE_MIGRATED_REVID=142853361

translator/src/main/java/com/google/devtools/j2objc/javac/JavacParser.java

@@ -98,6 +98,10 @@ private JavacFileManager getFileManager(JavaCompiler compiler,
     addPaths(StandardLocation.CLASS_PATH, classpathEntries, fileManager);
     addPaths(StandardLocation.SOURCE_PATH, sourcepathEntries, fileManager);
     addPaths(StandardLocation.PLATFORM_CLASS_PATH, Options.getBootClasspath(), fileManager);
+    List<String> processorPathEntries = options.getProcessorPathEntries();
+    if (!processorPathEntries.isEmpty()) {
+      addPaths(StandardLocation.ANNOTATION_PROCESSOR_PATH, processorPathEntries, fileManager);
+    }
     fileManager.setLocation(StandardLocation.CLASS_OUTPUT,
         Lists.newArrayList(options.fileUtil().getOutputDirectory()));
     fileManager.setLocation(StandardLocation.SOURCE_OUTPUT,
@@ -137,14 +141,6 @@ private List<String> getJavacOptions(boolean processAnnotations) {
     } else {
       javacOptions.add("-proc:none");
     }
-
-    // TODO(tball): this should be in the FileManager, but adding it there
-    // causes annotations to be processed twice, causing a "duplicate unit"
-    // error. Defining the path as a javac flag works correctly, however.
-    if (options.getProcessorPathEntries().size() > 0) {
-      javacOptions.add("-processorpath");
-      javacOptions.add(makePathString(options.getProcessorPathEntries()));
-    }
     return javacOptions;
   }