Add 64-bit windows cross-compiles

This is mostly the same as the existing 2ND_HOST / HOST_CROSS support.

The interesting thing I did here was make x86 the 'first' architecture,
and x86_64 the second. This way LOCAL_MULTILIB := first defaults to
32-bit windows modules.

  windows-x86/bin   <- defaults to 32-bit executables
  windows-x86/lib   <- 32-bit libraries, like before
  windows-x86/lib64 <- 64-bit libraries
  windows-x86/obj   <- 32-bit intermediates
  windows-x86/obj64 <- 64-bit intermediates

Then modules are registered with the names:

  host_cross_liblog    <- 32-bit, like before
  host_cross_liblog_64 <- 64-bit

Bug: 26957718
Change-Id: I9f119411acb43e973ec1e6bca3c1dc291c91556c
diff --git a/core/base_rules.mk b/core/base_rules.mk
index fcf3549..2fe0616 100644
--- a/core/base_rules.mk
+++ b/core/base_rules.mk
@@ -168,14 +168,14 @@
 endif
 
 my_register_name := $(LOCAL_MODULE)
-ifdef LOCAL_2ND_ARCH_VAR_PREFIX
-ifndef LOCAL_NO_2ND_ARCH_MODULE_SUFFIX
-my_register_name := $(LOCAL_MODULE)$($(my_prefix)2ND_ARCH_MODULE_SUFFIX)
-endif
-endif
 ifeq ($(my_host_cross),true)
   my_register_name := host_cross_$(LOCAL_MODULE)
 endif
+ifdef LOCAL_2ND_ARCH_VAR_PREFIX
+ifndef LOCAL_NO_2ND_ARCH_MODULE_SUFFIX
+my_register_name := $(my_register_name)$($(my_prefix)2ND_ARCH_MODULE_SUFFIX)
+endif
+endif
 # Make sure that this IS_HOST/CLASS/MODULE combination is unique.
 module_id := MODULE.$(if \
     $(LOCAL_IS_HOST_MODULE),$($(my_prefix)OS),TARGET).$(LOCAL_MODULE_CLASS).$(my_register_name)