feat(semver): hand-port constraint AND-split to drop look-around regex

The PCRE delimiter `(?<!^|as|[=>< ,]) *(?<!-)[, ](?!-) *(?!,|as|$)` used to
split AND-constraints relies on look-around, which the regex crate cannot
compile (parse_constraints panicked). Reproduce its semantics in a hand-written
`split_and_constraints` scanner shared by VersionParser and RootPackageLoader.

Also model `method_exists` for the class-name form (shirabe runs no dumped
Composer ClassLoader) and un-ignore the InstalledVersions tests, serialized via
`#[serial]` since they share global static state.

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

1 files changed, 1 insertions, 4 deletions

diff --git a/crates/shirabe/src/package/loader/root_package_loader.rs b/crates/shirabe/src/package/loader/root_package_loader.rs
index 16b905e..9cd1eac 100644
--- a/crates/shirabe/src/package/loader/root_package_loader.rs
+++ b/crates/shirabe/src/package/loader/root_package_loader.rs
@@ -322,10 +322,7 @@ impl RootPackageLoader {
 
             let or_split = Preg::split(r"\s*\|\|?\s*", req_version.trim());
             for or_constraint in &or_split {
-                let and_split = Preg::split(
-                    r"(?<!^|as|[=>< ,]) *(?<!-)[, ](?!-) *(?!,|as|$)",
-                    or_constraint,
-                );
+                let and_split = shirabe_semver::split_and_constraints(or_constraint);
                 for and_constraint in and_split {
                     constraints.push(and_constraint);
                 }