Build changes to build multilib tests

Test files will be emitted into directories for both first and second
target architectures. Going with the naming scheme for binaries,
single-architecture and 32b cases have the standard name, and
64b goes into a directory with "64" suffix.

In multi-architecture setups, the default concrete test targets are
extended with a "32" and "64" suffix, e.g., test-art-target-oat-JniTest64.
The suffix-less form is linked to the primary architecture target (usually 64).
That means running combined targets, e.g., test-art-target-oat, will only
test the primary architecture right now.

Fixed target run tests calling the right dalvikvm. Fixed library search
path for tests derived from CommonRuntimeTest.

Missing in this work-in-progress is correct handling of dex2oat for the
secondary architecture. To make it work on 64b, comment out line 101
in build/Android.executable.mk

Change-Id: I3d260994e6efe8b73b56c71994053cc9392943a9
diff --git a/runtime/common_runtime_test.h b/runtime/common_runtime_test.h
index 4b50cf4..723e32c 100644
--- a/runtime/common_runtime_test.h
+++ b/runtime/common_runtime_test.h
@@ -255,7 +255,11 @@
       filename += getenv("ANDROID_HOST_OUT");
       filename += "/framework/";
     } else {
+#ifdef __LP64__
+      filename += "/data/nativetest/art64/";
+#else
       filename += "/data/nativetest/art/";
+#endif
     }
     filename += "art-test-dex-";
     filename += name;