Allow Linux hosts to use ubsan runtime sanitizers.

Linux host prebuilts for UBSan runtime are available now, so we can
enable these. There's a bit more work to be done for Windows/Darwin
support, so that's left to another CL.

Bug: 148289941
Test: Build host binary with integer overflow sanitization enabled.
Test: ./art/test/testrunner/run_build_test_target.py art-linux-bionic-x64

Change-Id: Ie98979116fa3bb8accb23d1788adcc28330a9530
diff --git a/cc/config/x86_linux_host.go b/cc/config/x86_linux_host.go
index f08a379..13b5511 100644
--- a/cc/config/x86_linux_host.go
+++ b/cc/config/x86_linux_host.go
@@ -234,7 +234,7 @@
 }
 
 func (toolchainLinuxX86) LibclangRuntimeLibraryArch() string {
-	return "i686"
+	return "i386"
 }
 
 func (toolchainLinuxX8664) LibclangRuntimeLibraryArch() string {