Runtime support for CFI

Control Flow Integrity support in bionic.

General design:
http://clang.llvm.org/docs/ControlFlowIntegrityDesign.html#shared-library-support

This CL implements subsections "CFI Shadow" and "CFI_SlowPath" in the above document.

Bug: 22033465
Test: bionic device tests
Change-Id: I14dfea630de468eb5620e7f55f92b1397ba06217
diff --git a/tests/Android.bp b/tests/Android.bp
index 84be7bc..564ef03 100644
--- a/tests/Android.bp
+++ b/tests/Android.bp
@@ -295,6 +295,7 @@
     target: {
         android: {
             srcs: [
+                "cfi_test.cpp",
                 "dlext_test.cpp",
                 "libdl_test.cpp",
             ],