[JSC] Separate JSString::destroy and JSRopeString::destroy

https://bugs.webkit.org/show_bug.cgi?id=259388
rdar://112648672

Reviewed by Keith Miller.

We would like to separate them so that,

1. We can easily collect each sample from profiler.
2. We do not need to have isRope check for JSString case.

* Source/JavaScriptCore/heap/Heap.h:
* Source/JavaScriptCore/runtime/JSString.h:
(JSC::JSString::destroy): Deleted.
* Source/JavaScriptCore/runtime/JSStringInlines.h:
(JSC::JSString::destroy):
(JSC::JSRopeString::destroy):
(JSC::JSString::~JSString): Deleted.

Canonical link: https://commits.webkit.org/266206@main

Source/JavaScriptCore/heap/Heap.h

@@ -78,6 +78,7 @@ class JITStubRoutine;
 class JITStubRoutineSet;
 class JSCell;
 class JSImmutableButterfly;
+class JSRopeString;
 class JSString;
 class JSValue;
 class MachineThreads;
@@ -133,7 +134,7 @@ class Heap;
     v(propertyTableSpace, destructibleCellHeapCellType, PropertyTable) \
     v(regExpSpace, destructibleCellHeapCellType, RegExp) \
     v(regExpObjectSpace, cellHeapCellType, RegExpObject) \
-    v(ropeStringSpace, stringHeapCellType, JSRopeString) \
+    v(ropeStringSpace, ropeStringHeapCellType, JSRopeString) \
     v(scopedArgumentsSpace, cellHeapCellType, ScopedArguments) \
     v(sparseArrayValueMapSpace, destructibleCellHeapCellType, SparseArrayValueMap) \
     v(stringSpace, stringHeapCellType, JSString) \
@@ -943,6 +944,7 @@ class Heap {
     IsoHeapCellType moduleNamespaceObjectHeapCellType;
     IsoHeapCellType nativeStdFunctionHeapCellType;
     IsoInlinedHeapCellType<JSString> stringHeapCellType;
+    IsoInlinedHeapCellType<JSRopeString> ropeStringHeapCellType;
     IsoHeapCellType weakMapHeapCellType;
     IsoHeapCellType weakSetHeapCellType;
     JSDestructibleObjectHeapCellType destructibleObjectHeapCellType;

Source/JavaScriptCore/runtime/JSString.h

@@ -110,11 +110,8 @@ class JSString : public JSCell {
     static constexpr unsigned StructureFlags = Base::StructureFlags | OverridesGetOwnPropertySlot | InterceptsGetOwnPropertySlotByIndexEvenWhenLengthIsNotZero | StructureIsImmortal | OverridesPut;
 
     static constexpr bool needsDestruction = true;
-    static ALWAYS_INLINE void destroy(JSCell* cell)
-    {
-        static_cast<JSString*>(cell)->JSString::~JSString();
-    }
-
+    static void destroy(JSCell*);
+
     // We specialize the string subspace to get the fastest possible sweep. This wouldn't be
     // necessary if JSString didn't have a destructor.
     template<typename, SubspaceAccess>
@@ -201,8 +198,6 @@ class JSString : public JSCell {
     DECLARE_DEFAULT_FINISH_CREATION;
 
 public:
-    ~JSString();
-
     Identifier toIdentifier(JSGlobalObject*) const;
     AtomString toAtomString(JSGlobalObject*) const;
     AtomString toExistingAtomString(JSGlobalObject*) const;
@@ -292,6 +287,8 @@ class JSString : public JSCell {
 class JSRopeString final : public JSString {
     friend class JSString;
 public:
+    static void destroy(JSCell*);
+
     template<typename, SubspaceAccess>
     static GCClient::IsoSubspace* subspaceFor(VM& vm)
     {

Source/JavaScriptCore/runtime/JSStringInlines.h

@@ -30,12 +30,19 @@
 #include "KeyAtomStringCacheInlines.h"
 
 namespace JSC {
-
-inline JSString::~JSString()
+
+ALWAYS_INLINE void JSString::destroy(JSCell* cell)
+{
+    auto* string = static_cast<JSString*>(cell);
+    string->valueInternal().~String();
+}
+
+ALWAYS_INLINE void JSRopeString::destroy(JSCell* cell)
 {
-    if (isRope())
+    auto* string = static_cast<JSRopeString*>(cell);
+    if (string->isRope())
         return;
-    valueInternal().~String();
+    string->valueInternal().~String();
 }
 
 bool JSString::equal(JSGlobalObject* globalObject, JSString* other) const