refactor(preg): split the PREG_UNMATCHED_AS_NULL preg_* by flag

preg_match2() and preg_match_all_offset_capture() each become a pair over
a shared private impl, and their flags arguments are gone: no caller passed
anything but 0 or PREG_UNMATCHED_AS_NULL. Preg::match5()/is_match5() lose
their own flags argument for the same reason -- both call sites passed 0,
and the value had nowhere left to go -- so they are renumbered to
match4()/is_match4(). PREG_UNMATCHED_AS_NULL itself is now unreferenced.

Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>

2 files changed, 1 insertions, 5 deletions

diff --git a/crates/shirabe-symfony-console/src/formatter/output_formatter.rs b/crates/shirabe-symfony-console/src/formatter/output_formatter.rs
index 6ce96875..1a3de217 100644
--- a/crates/shirabe-symfony-console/src/formatter/output_formatter.rs
+++ b/crates/shirabe-symfony-console/src/formatter/output_formatter.rs
@@ -296,7 +296,6 @@ impl WrappableOutputFormatterInterface for OutputFormatter {
             format!("#<(({open_tag_regex}) | /({close_tag_regex})?)>#ix"),
             message,
             &mut matches,
-            0,
         );
         let full_matches = matches
             .get(&CaptureKey::ByIndex(0))
diff --git a/crates/shirabe-symfony-console/src/input/string_input.rs b/crates/shirabe-symfony-console/src/input/string_input.rs
index 1ec6e853..d6794957 100644
--- a/crates/shirabe-symfony-console/src/input/string_input.rs
+++ b/crates/shirabe-symfony-console/src/input/string_input.rs
@@ -58,7 +58,7 @@ impl StringInput {
             }
 
             let mut m: IndexMap<CaptureKey, Option<String>> = IndexMap::new();
-            if preg_match2(php_regex!(r"/\s+/A"), input, &mut m, 0, cursor as usize) {
+            if preg_match2(php_regex!(r"/\s+/A"), input, &mut m, cursor as usize) {
                 if token.is_some() {
                     tokens.push(token.take().unwrap());
                 }
@@ -68,7 +68,6 @@ impl StringInput {
                 format!(r#"/([^="'\s]+?)(=?)({}+)/A"#, Self::REGEX_QUOTED_STRING),
                 input,
                 &mut m,
-                0,
                 cursor as usize,
             ) {
                 let inner = shirabe_php_shim::substr(
@@ -91,7 +90,6 @@ impl StringInput {
                 format!(r"/{}/A", Self::REGEX_QUOTED_STRING),
                 input,
                 &mut m,
-                0,
                 cursor as usize,
             ) {
                 token = Some(format!(
@@ -109,7 +107,6 @@ impl StringInput {
                 format!(r"/{}/A", Self::REGEX_UNQUOTED_STRING),
                 input,
                 &mut m,
-                0,
                 cursor as usize,
             ) {
                 token = Some(format!(