Refine module name resolving in multilib build

-- Added TARGET_PREFER_32_BIT, which sets LOCAL_32_BIT_ONLY for an
   executable, if LOCAL_NO_2ND_ARCH is not true.

Name resolving in 64-bit multilib build:
-- Name resolving in PRODUCT_PACKAGES:
   foo:32 resolves to foo_32;
   foo:64 resolves to foo;
   foo resolves to both foo and foo_32 (if foo_32 is defined).

-- Name resolving for LOCAL_REQUIRED_MODULES:
   If a module is built for 2nd arch, its required module resolves to
   32-bit variant, if it exits;
   Otherwise for executable and shared library, a required module
   resolves to the default 64-bit variant; for other module classes,
   required module foo resolves to both foo and foo_32 (if foo_32 is
   defined)

Bug: 12898862
Change-Id: I5fda1a77f58814097b10b5ad2743ee25adfaecc4
diff --git a/core/base_rules.mk b/core/base_rules.mk
index a6af2bc..32e6b73 100644
--- a/core/base_rules.mk
+++ b/core/base_rules.mk
@@ -597,7 +597,8 @@
 ALL_MODULES.$(my_register_name).INSTALLED := \
     $(strip $(ALL_MODULES.$(my_register_name).INSTALLED) $(LOCAL_INSTALLED_MODULE))
 ALL_MODULES.$(my_register_name).REQUIRED := \
-    $(ALL_MODULES.$(my_register_name).REQUIRED) $(LOCAL_REQUIRED_MODULES) $(LOCAL_REQUIRED_MODULES_$(TARGET_$(LOCAL_2ND_ARCH_VAR_PREFIX)ARCH))
+    $(strip $(ALL_MODULES.$(my_register_name).REQUIRED) $(LOCAL_REQUIRED_MODULES) \
+      $(LOCAL_REQUIRED_MODULES_$(TARGET_$(LOCAL_2ND_ARCH_VAR_PREFIX)ARCH)))
 ALL_MODULES.$(my_register_name).EVENT_LOG_TAGS := \
     $(ALL_MODULES.$(my_register_name).EVENT_LOG_TAGS) $(event_log_tags)
 ALL_MODULES.$(my_register_name).INTERMEDIATE_SOURCE_DIR := \
@@ -608,6 +609,9 @@
 ALL_MODULES.$(my_register_name).OWNER := \
     $(sort $(ALL_MODULES.$(my_register_name).OWNER) $(LOCAL_MODULE_OWNER))
 endif
+ifdef LOCAL_2ND_ARCH_VAR_PREFIX
+ALL_MODULES.$(my_register_name).FOR_2ND_ARCH := true
+endif
 
 INSTALLABLE_FILES.$(LOCAL_INSTALLED_MODULE).MODULE := $(my_register_name)