Apply LOCAL_LDLIBS to target build rules too.

Use LOCAL_LDLIBS to link against prebuilt libraries (such as NDK
libraries).
Previously LOCAL_LDLIBS only applies to host modules and the behaviour
confuses users.

Change-Id: I515546d7b59ef54e8ef09050eb58ec63534c9291
diff --git a/core/combo/TARGET_linux-arm64.mk b/core/combo/TARGET_linux-arm64.mk
index 6bb3754..5e50f9f 100644
--- a/core/combo/TARGET_linux-arm64.mk
+++ b/core/combo/TARGET_linux-arm64.mk
@@ -180,7 +180,8 @@
 	$(PRIVATE_TARGET_GLOBAL_LDFLAGS) \
 	$(PRIVATE_LDFLAGS) \
 	$(PRIVATE_TARGET_LIBGCC) \
-	$(if $(filter true,$(PRIVATE_NO_CRT)),,$(PRIVATE_TARGET_CRTEND_SO_O))
+	$(if $(filter true,$(PRIVATE_NO_CRT)),,$(PRIVATE_TARGET_CRTEND_SO_O)) \
+	$(PRIVATE_LDLIBS)
 endef
 
 define transform-o-to-executable-inner
@@ -204,7 +205,8 @@
 	$(PRIVATE_TARGET_GLOBAL_LDFLAGS) \
 	$(PRIVATE_LDFLAGS) \
 	$(PRIVATE_TARGET_LIBGCC) \
-	$(if $(filter true,$(PRIVATE_NO_CRT)),,$(PRIVATE_TARGET_CRTEND_O))
+	$(if $(filter true,$(PRIVATE_NO_CRT)),,$(PRIVATE_TARGET_CRTEND_O)) \
+	$(PRIVATE_LDLIBS)
 endef
 
 define transform-o-to-static-executable-inner