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/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); \