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/binary.mk b/core/binary.mk
index 116e261..c8406d8 100644
--- a/core/binary.mk
+++ b/core/binary.mk
@@ -201,6 +201,8 @@
 b_lib :=
 endif
 
+my_linker := $($(LOCAL_2ND_ARCH_VAR_PREFIX)TARGET_LINKER)
+
 include $(BUILD_SYSTEM)/config_sanitizers.mk
 
 ifeq ($(strip $($(LOCAL_2ND_ARCH_VAR_PREFIX)WITHOUT_$(my_prefix)CLANG)),true)
@@ -361,6 +363,7 @@
   my_cxx := $(SYNTAX_TOOLS_PREFIX)/cxx-syntax $(my_syntax_arch) "$(my_cxx)"
 endif
 endif
+$(LOCAL_INTERMEDIATE_TARGETS): PRIVATE_LINKER := $(my_linker)
 $(LOCAL_INTERMEDIATE_TARGETS): PRIVATE_CXX := $(my_cxx)
 $(LOCAL_INTERMEDIATE_TARGETS): PRIVATE_CLANG := $(my_clang)