add a mayLoad property for machine instructions, a correlary to mayStore.
This is currently not set by anything.

llvm-svn: 45748
diff --git a/llvm/utils/TableGen/CodeGenInstruction.h b/llvm/utils/TableGen/CodeGenInstruction.h
index 6f7a19e..f3cdbfe 100644
--- a/llvm/utils/TableGen/CodeGenInstruction.h
+++ b/llvm/utils/TableGen/CodeGenInstruction.h
@@ -90,7 +90,7 @@
     bool isBarrier;
     bool isCall;
     bool isSimpleLoad;
-    bool mayStore;
+    bool mayLoad, mayStore;
     bool isImplicitDef;
     bool isPredicable;
     bool isConvertibleToThreeAddress;