Enable debugging of RS code under GDB

- Add/integrate GDBJITRegistrar support class for interfacing with GDB
-- Once the GDBJITRegistrar is merged into LLVM trunk (and AOSP upgrades LLVM)
   all files GDB* should be removed, and replaced with appropriate includes

- Basic [host|target]-side integration tests
-- host-tests: use bcc driver and clang to verify gdb output
-- target-tests: run skeleton apk on target and verify gdb output

- Add support for optimization_level metadata in bcinfo, libbcc
-- Disabled some LTO passes when optimization_level = 0
-- move register allocator registration after metadata inspection

- Initial version of android-commands.py GDB plugin (for test infrastructure)
-- relevant commands: load-android-app, run-android-app, start-android-app
-- tested versions: gdb (7.2, 7.3), python (2.6, 2.7)

- build 'bcc' driver tool by default in eng builds

Change-Id: I99e0c11c8591c6d911632c1dcc82dd8fbe1244a8
diff --git a/tests/Android.mk b/tests/Android.mk
index f57fe47..752e5ca 100644
--- a/tests/Android.mk
+++ b/tests/Android.mk
@@ -31,7 +31,7 @@
 LOCAL_C_INCLUDES := \
   $(LOCAL_PATH)/../include
 
-LOCAL_MODULE_TAGS := tests
+LOCAL_MODULE_TAGS := tests eng
 
 LOCAL_LDLIBS = -ldl