Force hunk storage migration to the modern format

Summary:
Ref T8475. This forces installs to migrate hunks to the modern format.

We stopped writing to the legacy format a very long time ago (2+ years?) without issues.

This doesn't destroy any data. T8623 has guidance and I'll publish more changelog guidance.

Test Plan: Faked some legacy data and migrated it.

Reviewers: chad

Reviewed By: chad

Maniphest Tasks: T8475

Differential Revision: https://secure.phabricator.com/D17039

resources/sql/autopatches/20161213.diff.01.hunks.php

@@ -0,0 +1,38 @@
+<?php
+
+$conn = id(new DifferentialRevision())->establishConnection('w');
+$src_table = 'differential_hunk';
+$dst_table = 'differential_hunk_modern';
+
+echo tsprintf(
+  "%s\n",
+  pht('Migrating old hunks...'));
+
+foreach (new LiskRawMigrationIterator($conn, $src_table) as $row) {
+  queryfx(
+    $conn,
+    'INSERT INTO %T
+      (changesetID, oldOffset, oldLen, newOffset, newLen,
+        dataType, dataEncoding, dataFormat, data,
+        dateCreated, dateModified)
+      VALUES
+      (%d, %d, %d, %d, %d,
+        %s, %s, %s, %s,
+        %d, %d)',
+    $dst_table,
+    $row['changesetID'],
+    $row['oldOffset'],
+    $row['oldLen'],
+    $row['newOffset'],
+    $row['newLen'],
+    DifferentialModernHunk::DATATYPE_TEXT,
+    'utf8',
+    DifferentialModernHunk::DATAFORMAT_RAW,
+    $row['changes'],
+    $row['dateCreated'],
+    $row['dateModified']);
+}
+
+echo tsprintf(
+  "%s\n",
+  pht('Done.'));