[GIT-PULLS] [php-src] PR #23127: Fix GH-23116 and GH-23117: stack overflow when normalizing a deeply nested document

Pull Request: https://github.com/php/php-src/pull/23127
Author: lazerg

`DOMNode::normalize()` and `Dom\Node::normalize()` walk the tree by recursing once per element child, so a deeply nested document exhausts the C stack and segfaults. Both now check the stack limit on entry and throw an `Error`, the same way the XML serializer has since GH-22570.

The throw is gated on `EG(exception)` because these functions return void: without it, unwinding through a tree that is wide at the overflow depth throws once per node and chains the Errors, which is quadratic.

Fixes #23116
Fixes #23117