C#: Clean up.

Author: aschackmull

config/identical-files.json

@@ -172,10 +172,6 @@
     "cpp/ql/lib/semmle/code/cpp/ir/implementation/raw/internal/reachability/PrintDominance.qll",
     "cpp/ql/lib/semmle/code/cpp/ir/implementation/unaliased_ssa/internal/reachability/PrintDominance.qll"
   ],
-  "C# ControlFlowReachability": [
-    "csharp/ql/lib/semmle/code/csharp/dataflow/internal/ControlFlowReachability.qll",
-    "csharp/ql/lib/semmle/code/csharp/dataflow/internal/rangeanalysis/ControlFlowReachability.qll"
-  ],
   "C++ ExternalAPIs": [
     "cpp/ql/src/Security/CWE/CWE-020/ExternalAPIs.qll",
     "cpp/ql/src/Security/CWE/CWE-020/ir/ExternalAPIs.qll"

csharp/ql/lib/semmle/code/csharp/dataflow/internal/ControlFlowReachability.qll

@@ -2,7 +2,6 @@ private import csharp
 private import DataFlowPublic
 private import DataFlowDispatch
 private import DataFlowImplCommon
-private import ControlFlowReachability
 private import FlowSummaryImpl as FlowSummaryImpl
 private import semmle.code.csharp.dataflow.FlowSummary as FlowSummary
 private import semmle.code.csharp.dataflow.internal.ExternalFlow
@@ -259,24 +258,6 @@ private module ThisFlow {
   }
 }
 
-/**
- * Holds if there is a control-flow path from `n1` to `n2`. `n2` is either an
- * expression node or an SSA definition node.
- */
-pragma[nomagic]
-predicate hasNodePath(ControlFlowReachabilityConfiguration conf, ExprNode n1, Node n2) {
-  exists(ControlFlow::Node cfn1, ControlFlow::Node cfn2 | conf.hasExprPath(_, cfn1, _, cfn2) |
-    cfn1 = n1.getControlFlowNode() and
-    cfn2 = n2.(ExprNode).getControlFlowNode()
-  )
-  or
-  exists(ControlFlow::Node cfn, AssignableDefinition def, ControlFlow::Node cfnDef |
-    conf.hasDefPath(_, cfn, def, cfnDef) and
-    cfn = n1.getControlFlowNode() and
-    n2 = TAssignableDefinitionNode(def, cfnDef)
-  )
-}
-
 /** Provides logic related to captured variables. */
 module VariableCapture {
   private import codeql.dataflow.VariableCapture as Shared

csharp/ql/lib/semmle/code/csharp/dataflow/internal/DataFlowPrivate.qll

@@ -4,7 +4,6 @@ private import FlowSummaryImpl as FlowSummaryImpl
 private import semmle.code.csharp.Caching
 private import semmle.code.csharp.dataflow.internal.DataFlowDispatch
 private import semmle.code.csharp.dataflow.internal.DataFlowPrivate
-private import semmle.code.csharp.dataflow.internal.ControlFlowReachability
 private import semmle.code.csharp.dispatch.Dispatch
 private import semmle.code.csharp.commons.ComparisonTest
 // import `TaintedMember` definitions from other files to avoid potential reevaluation