[X86][VMX] Tag VMX instructions scheduler classes

Tagged all as system instructions

llvm-svn: 320053
diff --git a/llvm/lib/Target/X86/X86Schedule.td b/llvm/lib/Target/X86/X86Schedule.td
index e35c1de..f56a33e 100644
--- a/llvm/lib/Target/X86/X86Schedule.td
+++ b/llvm/lib/Target/X86/X86Schedule.td
@@ -508,6 +508,7 @@
 def IIC_STR : InstrItinClass;
 def IIC_SKINIT : InstrItinClass;
 def IIC_SVM : InstrItinClass;
+def IIC_VMX : InstrItinClass;
 def IIC_CLGI : InstrItinClass;
 def IIC_STGI : InstrItinClass;
 def IIC_SWAPGS : InstrItinClass;