Do not underflow after resetting unmatched braces count
Do not underflow after resetting unmatched braces count

Fix #58638.

aidancully/rust,aidancully/rust,graydon/rust,aidancully/rust,aidancully/rust,graydon/rust,graydon/rust,aidancully/rust,graydon/rust,graydon/rust,aidancully/rust,graydon/rust