Merge #10506

10506: Add comment r=lnicola a=k-nasa

## Why


This code looks logic-bug ...


ce86534e1c/crates/syntax/src/syntax_node.rs (L50)


However, this code has been intentionally disabled.
It's a good idea to write a comment

ref: https://github.com/rust-analyzer/rust-analyzer/pull/10357

## What

- I added comment

Co-authored-by: k-nasa <htilcs1115@gmail.com>

crates/syntax/src/syntax_node.rs

@@ -47,6 +47,7 @@ impl SyntaxTreeBuilder {
 
     pub fn finish(self) -> Parse<SyntaxNode> {
         let (green, errors) = self.finish_raw();
+        // Disable block validation, see https://github.com/rust-analyzer/rust-analyzer/pull/10357
         if cfg!(debug_assertions) && false {
             let node = SyntaxNode::new_root(green.clone());
             crate::validation::validate_block_structure(&node);