ART: dex2oat flag for HGraphVisualizer dump file

This patch adds a new '--dump-cfg=<file>' flag to dex2oat which
specifies the file that HGraphVisualizer will store its output into.
Until now the graph was dumped to 'art.cfg' in the current working
directory. To make Checker work with run-test, the output directory
needs to be customizable.

Change-Id: I4a940f7708b88deea5a0e51d13aed13e52199349
diff --git a/compiler/driver/compiler_driver.cc b/compiler/driver/compiler_driver.cc
index 9985d66..e371807 100644
--- a/compiler/driver/compiler_driver.cc
+++ b/compiler/driver/compiler_driver.cc
@@ -339,7 +339,8 @@
                                const InstructionSetFeatures* instruction_set_features,
                                bool image, std::set<std::string>* image_classes,
                                std::set<std::string>* compiled_classes, size_t thread_count,
-                               bool dump_stats, bool dump_passes, CumulativeLogger* timer,
+                               bool dump_stats, bool dump_passes,
+                               const std::string& dump_cfg_file_name, CumulativeLogger* timer,
                                int swap_fd, const std::string& profile_file)
     : swap_space_(swap_fd == -1 ? nullptr : new SwapSpace(swap_fd, 10 * MB)),
       swap_space_allocator_(new SwapAllocator<void>(swap_space_.get())),
@@ -361,6 +362,7 @@
       stats_(new AOTCompilationStats),
       dump_stats_(dump_stats),
       dump_passes_(dump_passes),
+      dump_cfg_file_name_(dump_cfg_file_name),
       timings_logger_(timer),
       compiler_context_(nullptr),
       support_boot_image_fixup_(instruction_set != kMips),