Revert^2 "Fix CompilerDriver's handling of boot image extension."

This reverts commit 96d8585ebb9e21fc27a59ddd4173ca62ad93c194.

Fixed verification from oat files when compiling a boot
image extension. Normal verification can fail if the
primary boot image is quickened.

Test: `art/tools/buildbot-build.sh --target` with master-art manifest
Test: m test-art-host-gtest
Test: testrunner.py --host --optimizing
Bug: 119800099
Bug: 144751090
Change-Id: Ibc4e7ab1ec8451c9b5c87b6e87ab9807ac22e284
diff --git a/dex2oat/dex2oat.cc b/dex2oat/dex2oat.cc
index f1e7d8c..e23bedf 100644
--- a/dex2oat/dex2oat.cc
+++ b/dex2oat/dex2oat.cc
@@ -1936,6 +1936,8 @@
     if (!IsBootImage() && !IsBootImageExtension()) {
       class_loader =
           class_loader_context_->CreateClassLoader(compiler_options_->dex_files_for_oat_file_);
+    }
+    if (!IsBootImage()) {
       callbacks_->SetDexFiles(&dex_files);
     }