Add test mapping to run the libunwind tests.

Created a special target, libunwindstack_unit_test, that doesn't
include the test that dlopen's a shared library. It appears atest
doesn't understand how to handle the require keyword.

Also, move the shared library into the libunwindstack_test directory
itself.

Test: Ran atest libunwindstack_unit_test.
Change-Id: I967919b1d74a08669b61d0363d80861685725609

libunwindstack/Android.bp

@@ -153,12 +153,12 @@ cc_test_library {
     shared_libs: [
         "libunwindstack",
     ],
+    relative_install_path: "libunwindstack_test",
 }
 
-cc_test {
-    name: "libunwindstack_test",
+cc_defaults {
+    name: "libunwindstack_testlib_flags",
     defaults: ["libunwindstack_flags"],
-    isolated: true,
 
     srcs: [
         "tests/ArmExidxDecodeTest.cpp",
@@ -183,7 +183,6 @@ cc_test {
         "tests/ElfTestUtils.cpp",
         "tests/IsolatedSettings.cpp",
         "tests/JitDebugTest.cpp",
-        "tests/LocalUnwinderTest.cpp",
         "tests/LogFake.cpp",
         "tests/MapInfoCreateMemoryTest.cpp",
         "tests/MapInfoGetBuildIDTest.cpp",
@@ -253,11 +252,28 @@ cc_test {
         "tests/files/offline/straddle_arm/*",
         "tests/files/offline/straddle_arm64/*",
     ],
+}
+
+cc_test {
+    name: "libunwindstack_test",
+    defaults: ["libunwindstack_testlib_flags"],
+    isolated: true,
+
+    srcs: [
+        "tests/LocalUnwinderTest.cpp",
+    ],
     required: [
         "libunwindstack_local",
     ],
 }
 
+// Skip LocalUnwinderTest until atest understands required properly.
+cc_test {
+    name: "libunwindstack_unit_test",
+    defaults: ["libunwindstack_testlib_flags"],
+    isolated: true,
+}
+
 //-------------------------------------------------------------------------
 // Tools
 //-------------------------------------------------------------------------

libunwindstack/TEST_MAPPING

@@ -0,0 +1,7 @@
+{
+  "presubmit": [
+    {
+      "name": "libunwindstack_unit_test"
+    }
+  ]
+}

libunwindstack/tests/LocalUnwinderTest.cpp

@@ -170,10 +170,10 @@ TEST_F(LocalUnwinderTest, unwind_after_dlopen) {
 
   std::string testlib(testing::internal::GetArgvs()[0]);
   auto const value = testlib.find_last_of('/');
-  if (value == std::string::npos) {
-    testlib = "../";
+  if (value != std::string::npos) {
+    testlib = testlib.substr(0, value + 1);
   } else {
-    testlib = testlib.substr(0, value + 1) + "../";
+    testlib = "";
   }
   testlib += "libunwindstack_local.so";