rulec: Fix compiler after switch to NIO2 Paths

The compiler was broken in two ways that are trivially fixed:

- If $site_path/cache/rules directory already exists (e.g. other
  rules were already compiled) creation of the directory failed
  on local filesystem.

  Use createDirectories instead, which silently ignores existing
  directories.

- DELETE_ON_CLOSE for the temporary new JAR file holding the bytecode
  for the rules meant the JAR was deleted immediately after being
  packed and could not be renamed into the final destination.  This
  caused the compiler to fail with a rename error and never produce
  the cached bytecode.

  Omit the option.

Change-Id: Ib0855953ec7d1e4eb916946777d99e5c43513a1f

gerrit-server/src/main/java/com/google/gerrit/rules/PrologCompiler.java

@@ -14,8 +14,6 @@
 
 package com.google.gerrit.rules;
 
-import static java.nio.file.StandardOpenOption.DELETE_ON_CLOSE;
-
 import com.google.gerrit.common.TimeUtil;
 import com.google.gerrit.common.Version;
 import com.google.gerrit.reviewdb.client.RefNames;
@@ -98,11 +96,7 @@ public class PrologCompiler implements Callable<PrologCompiler.Status> {
     if (ruleDir == null) {
       throw new CompileException("Caching not enabled");
     }
-    try {
-      Files.createDirectory(ruleDir);
-    } catch (IOException e) {
-      throw new IOException("Cannot create " + ruleDir);
-    }
+    Files.createDirectories(ruleDir);
 
     File tempDir = File.createTempFile("GerritCodeReview_", ".rulec");
     if (!tempDir.delete() || !tempDir.mkdir()) {
@@ -243,7 +237,7 @@ public class PrologCompiler implements Callable<PrologCompiler.Status> {
 
     Path tmpjar =
         Files.createTempFile(archiveFile.getParent(), ".rulec_", ".jar");
-    try (OutputStream stream = Files.newOutputStream(tmpjar, DELETE_ON_CLOSE);
+    try (OutputStream stream = Files.newOutputStream(tmpjar);
         JarOutputStream out = new JarOutputStream(stream, mf)) {
       byte buffer[] = new byte[10240];
       // TODO: fixify this loop