refactor(pcre): drop the guards for unsupported preg flags

Preg::match5() rejected PREG_OFFSET_CAPTURE and check_set_order() rejected
PREG_SET_ORDER, mirroring the PHP where those flags would change the type
of $matches. The Rust ports of both take a typed `matches` out-param
instead, so neither flag can reach them; check_set_order() already had no
caller. The three constants are unreferenced once the guards are gone.

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

2 files changed, 2 insertions, 23 deletions

diff --git a/crates/shirabe-pcre/src/preg.rs b/crates/shirabe-pcre/src/preg.rs
index f45b86df..fb71c63b 100644
--- a/crates/shirabe-pcre/src/preg.rs
+++ b/crates/shirabe-pcre/src/preg.rs
@@ -14,9 +14,8 @@
 use indexmap::IndexMap;
 pub use shirabe_php_shim::CaptureKey;
 use shirabe_php_shim::{
-    PREG_OFFSET_CAPTURE, PREG_SET_ORDER, PREG_UNMATCHED_AS_NULL, PregPattern, preg_grep,
-    preg_match_all_offset_capture, preg_match_all2, preg_match2, preg_replace_callback,
-    preg_replace2,
+    PREG_UNMATCHED_AS_NULL, PregPattern, preg_grep, preg_match_all_offset_capture, preg_match_all2,
+    preg_match2, preg_replace_callback, preg_replace2,
 };
 
 #[derive(Debug)]
@@ -38,8 +37,6 @@ impl Preg {
         flags: i64,
         offset: usize,
     ) -> bool {
-        Self::check_offset_capture(flags, "matchWithOffsets");
-
         let mut internal: IndexMap<CaptureKey, Option<String>> = IndexMap::new();
         let result = preg_match2(
             pattern,
@@ -216,21 +213,6 @@ impl Preg {
     ) -> bool {
         Self::match_all_with_offsets5(pattern, subject, matches) > 0
     }
-
-    fn check_offset_capture(flags: i64, use_function_name: &str) {
-        assert!(
-            flags & PREG_OFFSET_CAPTURE == 0,
-            "PREG_OFFSET_CAPTURE is not supported as it changes the type of $matches, use {}() instead",
-            use_function_name
-        );
-    }
-
-    fn check_set_order(flags: i64) {
-        assert!(
-            flags & PREG_SET_ORDER == 0,
-            "PREG_SET_ORDER is not supported as it changes the type of $matches"
-        );
-    }
 }
 
 // Drops `null` (unmatched) groups, mirroring how the public `string`-valued
diff --git a/crates/shirabe-php-shim/src/preg.rs b/crates/shirabe-php-shim/src/preg.rs
index 6d70c717..62ad464c 100644
--- a/crates/shirabe-php-shim/src/preg.rs
+++ b/crates/shirabe-php-shim/src/preg.rs
@@ -1,9 +1,6 @@
 use indexmap::IndexMap;
 use std::sync::{Arc, LazyLock, Mutex};
 
-pub const PREG_PATTERN_ORDER: i64 = 1;
-pub const PREG_SET_ORDER: i64 = 2;
-pub const PREG_OFFSET_CAPTURE: i64 = 256;
 pub const PREG_UNMATCHED_AS_NULL: i64 = 512;
 
 #[derive(Debug, Clone, PartialOrd, Ord, PartialEq, Eq, Hash)]