fix(class-map-generator): avoid unsupported regex backreference/lookahead in heredoc detection

PhpFileCleaner's heredoc-start pattern used a `\1` backreference to
match the closing quote, and skip_heredoc's delimiter boundary check
used a `(?!...)` negative lookahead. The `regex` crate supports
neither, so it panicked with "invalid regex" whenever a scanned PHP
file contained a heredoc/nowdoc (e.g. vendor code pulled in via
`composer create-project`). The backreference is expanded into three
quote-state alternatives, and the lookahead becomes a direct check of
the next byte.

0 files changed, 0 insertions, 0 deletions