[JSC] Keeping Identifiers in PolymorphicAccessJITStubRoutine is not n…

…ecessary

https://bugs.webkit.org/show_bug.cgi?id=273610
rdar://127411952

Reviewed by Justin Michaud.

We are using shared JIT stub only for Baseline JIT IC, and ById case with Baseline JIT IC always has
CodeBlock which holds CacheableIdentifier. So JIT stub itself does not need to keep them.
When the stub is no longer used, then it gets zero-ref-count, and removed from shared JIT stub table automatically.

* Source/JavaScriptCore/jit/GCAwareJITStubRoutine.cpp:
(JSC::PolymorphicAccessJITStubRoutine::addedToSharedJITStubSet):
* Source/JavaScriptCore/jit/GCAwareJITStubRoutine.h:

Canonical link: https://commits.webkit.org/278268@main

Source/JavaScriptCore/jit/GCAwareJITStubRoutine.cpp

@@ -133,16 +133,6 @@ unsigned PolymorphicAccessJITStubRoutine::computeHash(const FixedVector<RefPtr<A
 void PolymorphicAccessJITStubRoutine::addedToSharedJITStubSet()
 {
     m_isInSharedJITStubSet = true;
-    // Since this stub no longer belongs to any CodeBlocks (since it is shared),
-    // identifiers need to be owned by this stub itself.
-    m_identifiers = FixedVector<Identifier>(m_cases.size());
-    unsigned index = 0;
-    for (auto& accessCase : m_cases) {
-        auto identifier = Identifier::fromUid(m_vm, accessCase->uid());
-        accessCase->updateIdentifier(CacheableIdentifier::createFromSharedStub(identifier.impl()));
-        m_identifiers[index] = WTFMove(identifier);
-        ++index;
-    }
 }
 
 MarkingGCAwareJITStubRoutine::MarkingGCAwareJITStubRoutine(

Source/JavaScriptCore/jit/GCAwareJITStubRoutine.h

@@ -122,7 +122,6 @@ class PolymorphicAccessJITStubRoutine : public GCAwareJITStubRoutine {
     VM& m_vm;
     FixedVector<RefPtr<AccessCase>> m_cases;
     FixedVector<StructureID> m_weakStructures;
-    FixedVector<Identifier> m_identifiers;
     RefPtr<WatchpointSet> m_watchpointSet;
     std::unique_ptr<WatchpointsOnStructureStubInfo> m_watchpoints;
 };