LibJS/JIT: Resolve the GetById property name at JIT time

We can resolve the IdentifierTableIndex to a DeprecatedFlyString& once
when jitting the code, instead of every time GetById executes.

Userland/Libraries/LibJS/Bytecode/CommonImplementations.cpp

@@ -35,14 +35,13 @@ ThrowCompletionOr<NonnullGCPtr<Object>> base_object_for_get(Bytecode::Interprete
     return base_value.to_object(vm);
 }
 
-ThrowCompletionOr<Value> get_by_id(Bytecode::Interpreter& interpreter, IdentifierTableIndex property, Value base_value, Value this_value, u32 cache_index)
+ThrowCompletionOr<Value> get_by_id(Bytecode::Interpreter& interpreter, DeprecatedFlyString const& property, Value base_value, Value this_value, u32 cache_index)
 {
     auto& vm = interpreter.vm();
-    auto const& name = interpreter.current_executable().get_identifier(property);
     auto& cache = interpreter.current_executable().property_lookup_caches[cache_index];
 
     if (base_value.is_string()) {
-        auto string_value = TRY(base_value.as_string().get(vm, name));
+        auto string_value = TRY(base_value.as_string().get(vm, property));
         if (string_value.has_value())
             return *string_value;
     }
@@ -58,7 +57,7 @@ ThrowCompletionOr<Value> get_by_id(Bytecode::Interpreter& interpreter, Identifie
     }
 
     CacheablePropertyMetadata cacheable_metadata;
-    auto value = TRY(base_obj->internal_get(name, this_value, &cacheable_metadata));
+    auto value = TRY(base_obj->internal_get(property, this_value, &cacheable_metadata));
 
     if (cacheable_metadata.type == CacheablePropertyMetadata::Type::OwnProperty) {
         cache.shape = shape;

Userland/Libraries/LibJS/Bytecode/CommonImplementations.h

@@ -13,7 +13,7 @@
 namespace JS::Bytecode {
 
 ThrowCompletionOr<NonnullGCPtr<Object>> base_object_for_get(Bytecode::Interpreter&, Value base_value);
-ThrowCompletionOr<Value> get_by_id(Bytecode::Interpreter&, IdentifierTableIndex, Value base_value, Value this_value, u32 cache_index);
+ThrowCompletionOr<Value> get_by_id(Bytecode::Interpreter&, DeprecatedFlyString const& property, Value base_value, Value this_value, u32 cache_index);
 ThrowCompletionOr<Value> get_by_value(Bytecode::Interpreter&, Value base_value, Value property_key_value);
 ThrowCompletionOr<Value> get_global(Bytecode::Interpreter&, IdentifierTableIndex, u32 cache_index);
 ThrowCompletionOr<void> put_by_property_key(VM&, Value base, Value this_value, Value value, PropertyKey name, Op::PropertyKind kind);

Userland/Libraries/LibJS/Bytecode/Interpreter.cpp

@@ -760,7 +760,7 @@ ThrowCompletionOr<void> SetLocal::execute_impl(Bytecode::Interpreter&) const
 ThrowCompletionOr<void> GetById::execute_impl(Bytecode::Interpreter& interpreter) const
 {
     auto base_value = interpreter.accumulator();
-    interpreter.accumulator() = TRY(get_by_id(interpreter, m_property, base_value, base_value, m_cache_index));
+    interpreter.accumulator() = TRY(get_by_id(interpreter, interpreter.current_executable().get_identifier(m_property), base_value, base_value, m_cache_index));
     return {};
 }
 
@@ -768,7 +768,7 @@ ThrowCompletionOr<void> GetByIdWithThis::execute_impl(Bytecode::Interpreter& int
 {
     auto base_value = interpreter.accumulator();
     auto this_value = interpreter.reg(m_this_value);
-    interpreter.accumulator() = TRY(get_by_id(interpreter, m_property, base_value, this_value, m_cache_index));
+    interpreter.accumulator() = TRY(get_by_id(interpreter, interpreter.current_executable().get_identifier(m_property), base_value, this_value, m_cache_index));
     return {};
 }
 

Userland/Libraries/LibJS/JIT/Compiler.cpp

@@ -919,7 +919,7 @@ void Compiler::compile_new_class(Bytecode::Op::NewClass const& op)
     store_accumulator(RET);
 }
 
-static Value cxx_get_by_id(VM& vm, Value base, Bytecode::IdentifierTableIndex property, u32 cache_index)
+static Value cxx_get_by_id(VM& vm, Value base, DeprecatedFlyString const& property, u32 cache_index)
 {
     return TRY_OR_SET_EXCEPTION(Bytecode::get_by_id(vm.bytecode_interpreter(), property, base, base, cache_index));
 }
@@ -929,7 +929,7 @@ void Compiler::compile_get_by_id(Bytecode::Op::GetById const& op)
     load_accumulator(ARG1);
     m_assembler.mov(
         Assembler::Operand::Register(ARG2),
-        Assembler::Operand::Imm(op.property().value()));
+        Assembler::Operand::Imm(bit_cast<u64>(&m_bytecode_executable.get_identifier(op.property()))));
     m_assembler.mov(
         Assembler::Operand::Register(ARG3),
         Assembler::Operand::Imm(op.cache_index()));
@@ -1575,7 +1575,7 @@ void Compiler::compile_resolve_super_base(Bytecode::Op::ResolveSuperBase const&)
     check_exception();
 }
 
-static Value cxx_get_by_id_with_this(VM& vm, Bytecode::IdentifierTableIndex property, Value base_value, Value this_value, u32 cache_index)
+static Value cxx_get_by_id_with_this(VM& vm, DeprecatedFlyString const& property, Value base_value, Value this_value, u32 cache_index)
 {
     return TRY_OR_SET_EXCEPTION(get_by_id(vm.bytecode_interpreter(), property, base_value, this_value, cache_index));
 }
@@ -1584,7 +1584,7 @@ void Compiler::compile_get_by_id_with_this(Bytecode::Op::GetByIdWithThis const&
 {
     m_assembler.mov(
         Assembler::Operand::Register(ARG1),
-        Assembler::Operand::Imm(op.property().value()));
+        Assembler::Operand::Imm(bit_cast<u64>(&m_bytecode_executable.get_identifier(op.property()))));
     load_accumulator(ARG2);
     load_vm_register(ARG3, op.this_value());
     m_assembler.mov(