Add execinfo functionality.

Bug: 27877410

Test: Add new unit tests.
Change-Id: Id5d7eb27a23f50e99a04f5ee1ab64047ba269bab
diff --git a/tests/Android.bp b/tests/Android.bp
index cbf0a9f..8a57dbb 100644
--- a/tests/Android.bp
+++ b/tests/Android.bp
@@ -474,6 +474,9 @@
                 // musl doesn't have error.h
                 "error_test.cpp",
 
+                // musl doesn't have execinfo.h
+                "execinfo_test.cpp",
+
                 // musl doesn't define noreturn for C++
                 "stdnoreturn_test.cpp",
 
@@ -745,6 +748,7 @@
         "dl_test.cpp",
         "dlfcn_symlink_support.cpp",
         "dlfcn_test.cpp",
+        "execinfo_test.cpp",
         "link_test.cpp",
         "pthread_dlfcn_test.cpp",
     ],
@@ -1141,6 +1145,7 @@
         "dlfcn_symlink_support.cpp",
         "dlfcn_test.cpp",
         "dl_test.cpp",
+        "execinfo_test.cpp",
         "gtest_globals.cpp",
         "gtest_main.cpp",
         "pthread_dlfcn_test.cpp",