Tell Soong about HOST_CROSS_*

This configures Soong to build windows binaries, which requires support
for 64-bit windows binaries in BUILD_PREBUILT for USE_SOONG=true.

module_arch_supported.mk did not support 64-bit being the secondary
architecture when evaluating multilib conditionals. All other uses of
HOST_*_IS_64_BIT already check the proper version.

(cherry picked from commit d6e3b841850d9a607eb9c841d9fa1836feedee5f)

Change-Id: I99cb69ea1756b8258f15d3630c75c9ffe277aaef
diff --git a/core/module_arch_supported.mk b/core/module_arch_supported.mk
index 9f05060..62e2643 100644
--- a/core/module_arch_supported.mk
+++ b/core/module_arch_supported.mk
@@ -12,7 +12,7 @@
 ## LOCAL_MODULE_HOST_OS
 ##
 ## Inputs from build system:
-## $(my_prefix)IS_64_BIT
+## $(LOCAL_2ND_ARCH_VAR_PREFIX)$(my_prefix)IS_64_BIT
 ## LOCAL_2ND_ARCH_VAR_PREFIX
 ##
 ## Outputs:
@@ -25,19 +25,18 @@
 my_module_arch_supported := false
 endif
 
-ifeq ($(LOCAL_2ND_ARCH_VAR_PREFIX),)
-ifeq ($($(my_prefix)IS_64_BIT)|$(my_module_multilib),true|32)
-my_module_arch_supported := false
-else ifeq ($($(my_prefix)IS_64_BIT)|$(my_module_multilib),|64)
+ifeq ($($(LOCAL_2ND_ARCH_VAR_PREFIX)$(my_prefix)IS_64_BIT)|$(my_module_multilib),true|32)
 my_module_arch_supported := false
 endif
-else # LOCAL_2ND_ARCH_VAR_PREFIX
+ifeq ($($(LOCAL_2ND_ARCH_VAR_PREFIX)$(my_prefix)IS_64_BIT)|$(my_module_multilib),|64)
+my_module_arch_supported := false
+endif
+
+ifneq ($(LOCAL_2ND_ARCH_VAR_PREFIX),)
 ifeq ($(my_module_multilib),first)
 my_module_arch_supported := false
-else ifeq ($(my_module_multilib),64)
-my_module_arch_supported := false
 endif
-endif # LOCAL_2ND_ARCH_VAR_PREFIX
+endif
 
 ifneq (,$(LOCAL_MODULE_$(my_prefix)ARCH))
 ifeq (,$(filter $($(my_prefix)$(LOCAL_2ND_ARCH_VAR_PREFIX)ARCH),$(LOCAL_MODULE_$(my_prefix)ARCH)))
diff --git a/core/prebuilt.mk b/core/prebuilt.mk
index ed25f71..caa9909 100644
--- a/core/prebuilt.mk
+++ b/core/prebuilt.mk
@@ -72,6 +72,26 @@
 endif
 LOCAL_HOST_PREFIX :=
 endif
+
+ifdef HOST_CROSS_2ND_ARCH
+my_prefix := HOST_CROSS_
+LOCAL_2ND_ARCH_VAR_PREFIX := $($(my_prefix)2ND_ARCH_VAR_PREFIX)
+LOCAL_HOST_PREFIX := $(my_prefix)
+include $(BUILD_SYSTEM)/module_arch_supported.mk
+ifeq ($(my_module_arch_supported),true)
+$(warning $(LOCAL_MODULE) $(LOCAL_2ND_ARCH_VAR_PREFIX))
+OVERRIDE_BUILT_MODULE_PATH :=
+LOCAL_BUILT_MODULE :=
+LOCAL_INSTALLED_MODULE :=
+LOCAL_MODULE_STEM :=
+LOCAL_BUILT_MODULE_STEM :=
+LOCAL_INSTALLED_MODULE_STEM :=
+LOCAL_INTERMEDIATE_TARGETS :=
+include $(BUILD_SYSTEM)/prebuilt_internal.mk
+endif
+LOCAL_HOST_PREFIX :=
+LOCAL_2ND_ARCH_VAR_PREFIX :=
+endif
 endif
 endif
 
diff --git a/core/soong.mk b/core/soong.mk
index 646c68e..578aac9 100644
--- a/core/soong.mk
+++ b/core/soong.mk
@@ -45,7 +45,11 @@
 	echo '    "DeviceSecondaryAbi": ["$(TARGET_2ND_CPU_ABI)", "$(TARGET_2ND_CPU_ABI2)"],'; \
 	echo ''; \
 	echo '    "HostArch": "$(HOST_ARCH)",'; \
-	echo '    "HostSecondaryArch": "$(HOST_2ND_ARCH)"'; \
+	echo '    "HostSecondaryArch": "$(HOST_2ND_ARCH)",'; \
+	echo ''; \
+	echo '    "CrossHost": "$(HOST_CROSS_OS)",'; \
+	echo '    "CrossHostArch": "$(HOST_CROSS_ARCH)",'; \
+	echo '    "CrossHostSecondaryArch": "$(HOST_CROSS_2ND_ARCH)"'; \
 	echo '}') > $(SOONG_VARIABLES_TMP); \
 	if ! cmp -s $(SOONG_VARIABLES_TMP) $(SOONG_VARIABLES); then \
 	  mv $(SOONG_VARIABLES_TMP) $(SOONG_VARIABLES); \