Call lld with --pack-dyn-relocs=none if my_pack_module_relocations is false

* Factor out the logic that sets up my_pack_module_relocations
  from dynamic_binary.mk to pack_dyn_relocs_setup.mk.
* Use stand-alone relocation_packer only if my_pack_module_relocations
  is true and my_use_clang_lld is false.

Bug: 80093890
Bug: 73768157
Test: build and boot with USE_CLANG_LLD=true
Change-Id: I7c4b5fcdce0754c57cff4acf86185cac65a26c40

core/pack_dyn_relocs_setup.mk

@@ -0,0 +1,33 @@
+#############################################################
+## Set up my_pack_module_relocations
+## Input variables:
+##   DISABLE_RELOCATION_PACKER,
+##   LOCAL_PACK_MODULE_RELOCATIONS*,
+##   *TARGET_PACK_MODULE_RELOCATIONS,
+##   LOCAL_MODULE_CLASS, HOST_OS
+## Output variables:
+##   my_pack_module_relocations, if false skip relocation_packer
+#############################################################
+
+my_pack_module_relocations := false
+ifneq ($(DISABLE_RELOCATION_PACKER),true)
+  my_pack_module_relocations := $(firstword \
+    $(LOCAL_PACK_MODULE_RELOCATIONS_$($(my_prefix)$(LOCAL_2ND_ARCH_VAR_PREFIX)ARCH)) \
+    $(LOCAL_PACK_MODULE_RELOCATIONS))
+endif
+
+ifeq ($(my_pack_module_relocations),)
+  my_pack_module_relocations := $($(LOCAL_2ND_ARCH_VAR_PREFIX)TARGET_PACK_MODULE_RELOCATIONS)
+endif
+
+# Do not pack relocations for executables. Because packing results in
+# non-zero p_vaddr which causes kernel to load executables to lower
+# address (starting at 0x8000) http://b/20665974
+ifneq ($(filter EXECUTABLES NATIVE_TESTS,$(LOCAL_MODULE_CLASS)),)
+  my_pack_module_relocations := false
+endif
+
+# TODO (dimitry): Relocation packer is not yet available for darwin
+ifneq ($(HOST_OS),linux)
+  my_pack_module_relocations := false
+endif