Update FIXME. ABM is already covered by LZCNT and POPCNT.

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@157676 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/Headers/x86intrin.h b/lib/Headers/x86intrin.h
index 131e433..cdbf439 100644
--- a/lib/Headers/x86intrin.h
+++ b/lib/Headers/x86intrin.h
@@ -54,6 +54,6 @@
 #include <fma4intrin.h>
 #endif
 
-// FIXME: XOP, LWP, ABM
+// FIXME: XOP, LWP
 
 #endif /* __X86INTRIN_H */