Move .oat files to ELF format

Generates .oat in ELF file format using MCLinker
- Uses MCLinker IRBuilder to create a synthetic .o from OatWriter output.
- Uses new ElfFile for prelinking to support art image optimizations.

Adapted OatFile to load using dlopen, ElfFile, or memory, removing raw MemMap mechanism.

Changed image code to not assume oat data will be immediately after
image to allow space for ELF headers.

Passes test-art and works with installd.

Change-Id: Idc026eddb5de93f4b97490c405f3ed7b39589749
diff --git a/build/Android.gtest.mk b/build/Android.gtest.mk
index c3674f2..5f518a4 100644
--- a/build/Android.gtest.mk
+++ b/build/Android.gtest.mk
@@ -72,6 +72,7 @@
     LOCAL_SHARED_LIBRARIES += libdl libicuuc libicui18n libnativehelper libstlport libz libcutils
     LOCAL_STATIC_LIBRARIES += libgtest
     LOCAL_MODULE_PATH := $(ART_NATIVETEST_OUT)
+    include $(LLVM_DEVICE_BUILD_MK)
     include $(BUILD_EXECUTABLE)
     art_gtest_exe := $$(LOCAL_MODULE_PATH)/$$(LOCAL_MODULE)
     ART_TARGET_TEST_EXECUTABLES += $$(art_gtest_exe)
@@ -83,6 +84,7 @@
       # Mac OS complains about unresolved symbols if you don't include this.
       LOCAL_WHOLE_STATIC_LIBRARIES := libgtest_host
     endif
+    include $(LLVM_HOST_BUILD_MK)
     include $(BUILD_HOST_EXECUTABLE)
     art_gtest_exe := $(HOST_OUT_EXECUTABLES)/$$(LOCAL_MODULE)
     ART_HOST_TEST_EXECUTABLES += $$(art_gtest_exe)