Move code related to debug info generation to its own directory.

debug/dwarf/ contains helper classes which hide the details
of the DWARF file format. It acts as independent DWARF library.

debug/ contains ART-specific code which generates ELF debug
sections (which includes non-DWARF sections like .symtab).

Change-Id: Id351f604e4e64be2ca395a78324ea02e30481497
diff --git a/build/Android.gtest.mk b/build/Android.gtest.mk
index e3f0c24..704d69a 100644
--- a/build/Android.gtest.mk
+++ b/build/Android.gtest.mk
@@ -239,13 +239,13 @@
   runtime/proxy_test.cc \
   runtime/reflection_test.cc \
   compiler/compiled_method_test.cc \
+  compiler/debug/dwarf/dwarf_test.cc \
   compiler/dex/gvn_dead_code_elimination_test.cc \
   compiler/dex/global_value_numbering_test.cc \
   compiler/dex/local_value_numbering_test.cc \
   compiler/dex/mir_graph_test.cc \
   compiler/dex/mir_optimization_test.cc \
   compiler/dex/type_inference_test.cc \
-  compiler/dwarf/dwarf_test.cc \
   compiler/driver/compiled_method_storage_test.cc \
   compiler/driver/compiler_driver_test.cc \
   compiler/elf_writer_test.cc \