Fix missed rename.

Author: munificent

lib/src/ast_extensions.dart

@@ -458,7 +458,7 @@ extension AdjacentStringsExtensions on AdjacentStrings {
   ///
   /// To balance these, we omit the indentation when an adjacent string
   /// expression is in a context where it's unlikely to be confusing.
-  bool get indentStrings3_7 {
+  bool get indentStrings3Dot7 {
     return switch (parent) {
       ArgumentList(:var arguments) => _hasOtherStringArgument(arguments),
 

lib/src/front_end/ast_node_visitor.dart

@@ -143,7 +143,7 @@ final class AstNodeVisitor extends ThrowingAstVisitor<void> with PieceFactory {
 
   @override
   void visitAdjacentStrings(AdjacentStrings node) {
-    var indent = style.is3Dot7 ? node.indentStrings3_7 : node.indentStrings;
+    var indent = style.is3Dot7 ? node.indentStrings3Dot7 : node.indentStrings;
     var piece = InfixPiece(
       node.strings.map(nodePiece).toList(),
       indent: indent ? Indent.infix : Indent.none,