Init .gnu_debugdata in GetElf().

- Modify the tests to share some code for the generation of the elf data.
- Move the gnu_debugdata files into a separate directory.
- Add tests for GetElf().
- Move the CreateMemory() tests and the GetElf() tests into separate files.

Bug: 23762183

Test: New unit tests pass.
Change-Id: Ie3380296bb49753c2ac8801cfa11f93d6ff7121d
diff --git a/libunwindstack/Android.bp b/libunwindstack/Android.bp
index 8776db7..5445f6e 100644
--- a/libunwindstack/Android.bp
+++ b/libunwindstack/Android.bp
@@ -98,8 +98,10 @@
         "tests/ElfInterfaceArmTest.cpp",
         "tests/ElfInterfaceTest.cpp",
         "tests/ElfTest.cpp",
+        "tests/ElfTestUtils.cpp",
         "tests/LogFake.cpp",
-        "tests/MapInfoTest.cpp",
+        "tests/MapInfoCreateMemoryTest.cpp",
+        "tests/MapInfoGetElfTest.cpp",
         "tests/MapsTest.cpp",
         "tests/MemoryFake.cpp",
         "tests/MemoryFileTest.cpp",
@@ -144,8 +146,8 @@
     ],
 
     data: [
-        "tests/elf32.xz",
-        "tests/elf64.xz",
+        "tests/files/elf32.xz",
+        "tests/files/elf64.xz",
     ],
 }