unified: Simplify with getParentIndex

Author: asgerf

unified/ql/lib/codeql/unified/internal/LocalNameBinding.qll

@@ -70,45 +70,10 @@ private module LocalNameBindingInput implements LocalNameBindingInputSig<Locatio
   }
 
   private AstNode getChild1(AstNode n, int index) {
-    result = n.(Block).getStmt(index) and
-    not n instanceof BlockWithGuardStmts
-    or
     result = n.(BlockWithGuardStmts).getTranslatedChild(index)
     or
     result = n.(LogicalAndRoot).getNthLeaf(index)
     or
-    exists(PatternGuardExpr guard | n = guard |
-      index = 0 and result = guard.getPattern()
-      or
-      index = 1 and result = guard.getValue()
-    )
-    or
-    exists(IfExpr expr | n = expr |
-      index = 0 and result = expr.getCondition()
-      or
-      index = 1 and result = expr.getThen()
-      or
-      index = 2 and result = expr.getElse()
-    )
-    or
-    exists(VariableDeclaration decl | n = decl |
-      index = 0 and result = decl.getPattern()
-      or
-      index = 1 and result = decl.getType()
-      or
-      index = 2 and result = decl.getValue()
-    )
-    or
-    exists(FunctionExpr expr | n = expr |
-      result = expr.getCaptureDeclaration(index)
-      or
-      // Put other children after the capture declarations.
-      // They act as sibling-shadowing declarations, so they are in scope with in the other children.
-      result = expr.getAFieldOrChild() and
-      not result = expr.getACaptureDeclaration() and
-      index = count(expr.getACaptureDeclaration())
-    )
-    or
     index = 0 and
     relocatedClassMember(n, result)
   }
@@ -131,7 +96,7 @@ private module LocalNameBindingInput implements LocalNameBindingInputSig<Locatio
     not n instanceof LogicalAndExpr and // also ignore intermediate nodes within a 'logical and' tree
     not n instanceof GuardIfStmt and
     not relocatedClassMember(_, result) and
-    index = 0 and
+    index = result.getParentIndex() and
     result = n.getAFieldOrChild()
   }