X86: Get X86_FS to compile.

--HG--
extra : convert_revision : fb973bcf13648876d5691231845dd47a2be50f01
diff --git a/build_opts/X86_FS b/build_opts/X86_FS
new file mode 100644
index 0000000..7cc6847
--- /dev/null
+++ b/build_opts/X86_FS
@@ -0,0 +1,3 @@
+TARGET_ISA = 'x86'
+CPU_MODELS = 'AtomicSimpleCPU,TimingSimpleCPU'
+FULL_SYSTEM = 1