Support cc_test_host

Support cc_test_host for gtest tests compiled for the host.

Change-Id: I632d2c211075ba9391d934609f1bf368459397e1
diff --git a/cmd/soong_build/main.go b/cmd/soong_build/main.go
index c1f8243..23bcb56 100644
--- a/cmd/soong_build/main.go
+++ b/cmd/soong_build/main.go
@@ -54,6 +54,7 @@
 	ctx.RegisterModuleType("cc_library_host_static", cc.CCLibraryHostStaticFactory)
 	ctx.RegisterModuleType("cc_library_host_shared", cc.CCLibraryHostSharedFactory)
 	ctx.RegisterModuleType("cc_binary_host", cc.CCBinaryHostFactory)
+	ctx.RegisterModuleType("cc_test_host", cc.CCTestHostFactory)
 
 	ctx.RegisterModuleType("gensrcs", genrule.GenSrcsFactory)