Use a different linker for ASan binaries.

Another change in bionic/linker adds linker_asan/linker_asan64 that
know where to find ASan shared libraries.
Also, include linker_asan to the required packages list when building
for ASan.

Change-Id: I8ebe7c0091bbeb0c135708a891d33d9844373d37
diff --git a/core/config_sanitizers.mk b/core/config_sanitizers.mk
index c911891..c28fff1 100644
--- a/core/config_sanitizers.mk
+++ b/core/config_sanitizers.mk
@@ -92,6 +92,7 @@
                            $(ADDRESS_SANITIZER_CONFIG_EXTRA_SHARED_LIBRARIES)
     my_static_libraries += $(ADDRESS_SANITIZER_CONFIG_EXTRA_STATIC_LIBRARIES)
     my_ldflags += -Wl,-rpath,$($(LOCAL_2ND_ARCH_VAR_PREFIX)ADDRESS_SANITIZER_RPATH)
+    my_linker := $($(LOCAL_2ND_ARCH_VAR_PREFIX)ADDRESS_SANITIZER_LINKER)
   endif
 endif