Shared CFG: Rename TNode to TCfgNode

This is in order to avoid name clash with the often so-named IPA type for data-
flow nodes. The name clash is not problematic because they are both in scope,
but because (cached) IPA types with overlapping names are known to sometimes
result in re-evaluation of cached stages, when one of the IPA types gets an
internal `#2` suffix in one query run, and the other IPA type gets the suffix
in another run.

Author: hvitved

csharp/ql/lib/semmle/code/csharp/controlflow/ControlFlowGraph.qll

@@ -25,7 +25,7 @@ module ControlFlow {
    * Only nodes that can be reached from the callable entry point are included in
    * the CFG.
    */
-  class Node extends TNode {
+  class Node extends TCfgNode {
     /** Gets a textual representation of this control flow node. */
     string toString() { none() }
 

csharp/ql/lib/semmle/code/csharp/controlflow/internal/ControlFlowGraphImplShared.qll

@@ -788,7 +788,7 @@ private module Cached {
    * The control flow graph is pruned for unreachable nodes.
    */
   cached
-  newtype TNode =
+  newtype TCfgNode =
     TEntryNode(CfgScope scope) { succEntrySplits(scope, _, _, _) } or
     TAnnotatedExitNode(CfgScope scope, boolean normal) {
       exists(Reachability::SameSplitsBlock b, SuccessorType t | b.isReachable(_) |
@@ -807,7 +807,7 @@ private module Cached {
 
   /** Gets a successor node of a given flow type, if any. */
   cached
-  TNode getASuccessor(TNode pred, SuccessorType t) {
+  TCfgNode getASuccessor(TCfgNode pred, SuccessorType t) {
     // Callable entry node -> callable body
     exists(ControlFlowElement succElement, Splits succSplits, CfgScope scope |
       result = TElementNode(succElement, succSplits) and

ruby/ql/lib/codeql/ruby/controlflow/ControlFlowGraph.qll

@@ -27,7 +27,7 @@ class CfgScope extends Scope instanceof CfgScope::Range_ {
  *
  * Only nodes that can be reached from an entry point are included in the CFG.
  */
-class CfgNode extends TNode {
+class CfgNode extends TCfgNode {
   /** Gets a textual representation of this control flow node. */
   string toString() { none() }
 

ruby/ql/lib/codeql/ruby/controlflow/internal/ControlFlowGraphImplShared.qll

@@ -788,7 +788,7 @@ private module Cached {
    * The control flow graph is pruned for unreachable nodes.
    */
   cached
-  newtype TNode =
+  newtype TCfgNode =
     TEntryNode(CfgScope scope) { succEntrySplits(scope, _, _, _) } or
     TAnnotatedExitNode(CfgScope scope, boolean normal) {
       exists(Reachability::SameSplitsBlock b, SuccessorType t | b.isReachable(_) |
@@ -807,7 +807,7 @@ private module Cached {
 
   /** Gets a successor node of a given flow type, if any. */
   cached
-  TNode getASuccessor(TNode pred, SuccessorType t) {
+  TCfgNode getASuccessor(TCfgNode pred, SuccessorType t) {
     // Callable entry node -> callable body
     exists(ControlFlowElement succElement, Splits succSplits, CfgScope scope |
       result = TElementNode(succElement, succSplits) and