Explicitly add lld's relr relocation flags for Android Pie and above

Bug: http://b/119086751

https://android-review.googlesource.com/c/837025 disabled lld relocation
packing globally and enabled it for soong modules targeting pie and
above.  Turn it on for Android.mk modules as well.

Test: grep for -Wl,pack-dyn-relocs=android in
      out/build-aosp_<device>.ninja

Change-Id: I81b8625073aa6b364219b8cf3122b69c95ec7589

core/binary.mk

@@ -1614,7 +1614,9 @@ my_target_global_cppflags := $($(LOCAL_2ND_ARCH_VAR_PREFIX)CLANG_$(my_prefix)GLO
 ifeq ($(my_use_clang_lld),true)
   my_target_global_ldflags := $($(LOCAL_2ND_ARCH_VAR_PREFIX)CLANG_$(my_prefix)GLOBAL_LLDFLAGS)
   include $(BUILD_SYSTEM)/pack_dyn_relocs_setup.mk
-  ifeq ($(my_pack_module_relocations),false)
+  ifeq ($(my_pack_module_relocations),true)
+    my_target_global_ldflags += -Wl,--pack-dyn-relocs=android+relr -Wl,--use-android-relr-tags
+  else
     my_target_global_ldflags += -Wl,--pack-dyn-relocs=none
   endif
 else

core/pack_dyn_relocs_setup.mk

@@ -32,3 +32,12 @@ ifdef LOCAL_IS_HOST_MODULE
   # Do not pack relocations on host modules
   my_pack_module_relocations := false
 endif
+
+# Lld relocation packing cannot be enabled for binaries before Android Pie.
+ifneq ($(LOCAL_SDK_VERSION),)
+  ifneq ($(LOCAL_SDK_VERSION),current)
+    ifeq ($(call math_lt,$(LOCAL_SDK_VERSION),28),true)
+      my_pack_module_relocations := false
+    endif
+  endif
+endif