Hotfix: Go: exclude method receivers from dead-store-of-field query

Author: smowton

go/ql/src/RedundantCode/DeadStoreOfField.ql

@@ -38,6 +38,9 @@ predicate escapes(DataFlow::Node nd) {
   // if `nd` is passed to a function, then it escapes
   nd = any(DataFlow::CallNode c).getASyntacticArgument()
   or
+  // if `nd` is the receiver of a function, then it escapes
+  nd = any(DataFlow::MethodCallNode c).getReceiver()
+  or
   // if `nd` has its address taken, then it escapes
   exists(AddressExpr ae | nd.asExpr() = ae.getOperand())
   or