Allow to build native tests for translation arch only.

- To build a native test for translation arch only, use:
  LOCAL_MODULE_TARGET_ARCH := <translation arch>
- Also disable building .odex for translation arch for Java libraries.

Bug: 27526885
Change-Id: I063e8876781c4424da7abebf1b9b7cb842ce205f

core/dex_preopt_odex_install.mk

@@ -68,10 +68,12 @@ include $(BUILD_SYSTEM)/setup_one_odex.mk
 # #################################################
 # Odex for the 2nd arch
 ifdef TARGET_2ND_ARCH
+ifneq ($(TARGET_TRANSLATE_2ND_ARCH),true)
 ifneq (first,$(my_module_multilib))
 my_2nd_arch_prefix := $(TARGET_2ND_ARCH_VAR_PREFIX)
 include $(BUILD_SYSTEM)/setup_one_odex.mk
 endif  # my_module_multilib is not first.
+endif  # TARGET_TRANSLATE_2ND_ARCH not true
 endif  # TARGET_2ND_ARCH
 # #################################################
 else  # must be APPS

core/executable.mk

@@ -18,8 +18,13 @@ endif
 ifneq (true,$(my_skip_this_target))
 
 ifeq ($(TARGET_TRANSLATE_2ND_ARCH),true)
+# If a native test explicity specifies to build only for the translation arch,
+# we'll still need LOCAL_MULTILIB=both and let module_arch_supported.mk choose
+# to build only for TARGET_2ND_ARCH.
+ifneq (1,$(words $(LOCAL_MODULE_TARGET_ARCH)))
 LOCAL_MULTILIB := first
 endif
+endif
 
 my_prefix := TARGET_
 include $(BUILD_SYSTEM)/multilib.mk