Revert "Simplify arch target handling"

This reverts commit 6713fb26cbcadf525cd75e47d7d0cbc23d282b3e.

Change-Id: Ic473cea2563b0b37dc08b0bc5d3a0ac8c4b6afe6
diff --git a/cc/x86_linux_host.go b/cc/x86_linux_host.go
index b2d8462..a75de90 100644
--- a/cc/x86_linux_host.go
+++ b/cc/x86_linux_host.go
@@ -254,6 +254,6 @@
 }
 
 func init() {
-	registerToolchainFactory(android.Linux, android.X86, linuxX86ToolchainFactory)
-	registerToolchainFactory(android.Linux, android.X86_64, linuxX8664ToolchainFactory)
+	registerHostToolchainFactory(android.Linux, android.X86, linuxX86ToolchainFactory)
+	registerHostToolchainFactory(android.Linux, android.X86_64, linuxX8664ToolchainFactory)
 }