Clean some dex2oat options.

Remove dump-passes inherited from Quick days,
and move dump-timings and dump-stats to CompilerStats.

Test: test.py
Change-Id: Ie79be858a141e59dc0b2a87d8cb5a5248a5bc7af
diff --git a/compiler/driver/compiler_options.cc b/compiler/driver/compiler_options.cc
index 032763c..c0a9a05 100644
--- a/compiler/driver/compiler_options.cc
+++ b/compiler/driver/compiler_options.cc
@@ -49,6 +49,8 @@
       implicit_so_checks_(true),
       implicit_suspend_checks_(false),
       compile_pic_(false),
+      dump_timings_(false),
+      dump_stats_(false),
       verbose_methods_(),
       abort_on_hard_verifier_failure_(false),
       abort_on_soft_verifier_failure_(false),