LibJS/JIT: Store the running ExecutionContext& in a dedicated register

Userland/Libraries/LibJS/JIT/Compiler.cpp

@@ -2061,6 +2061,10 @@ OwnPtr<NativeExecutable> Compiler::compile(Bytecode::Executable& bytecode_execut
         Assembler::Operand::Register(LOCALS_ARRAY_BASE),
         Assembler::Operand::Register(ARG2));
 
+    compiler.m_assembler.mov(
+        Assembler::Operand::Register(RUNNING_EXECUTION_CONTEXT_BASE),
+        Assembler::Operand::Register(ARG4));
+
     compiler.reload_cached_accumulator();
 
     Assembler::Label normal_entry {};

Userland/Libraries/LibJS/JIT/Compiler.h

@@ -38,6 +38,7 @@ private:
     static constexpr auto REGISTER_ARRAY_BASE = Assembler::Reg::RBX;
     static constexpr auto LOCALS_ARRAY_BASE = Assembler::Reg::R14;
     static constexpr auto CACHED_ACCUMULATOR = Assembler::Reg::R13;
+    static constexpr auto RUNNING_EXECUTION_CONTEXT_BASE = Assembler::Reg::R15;
 #    endif
 
 #    define JS_ENUMERATE_COMMON_BINARY_OPS_WITHOUT_FAST_PATH(O) \

Userland/Libraries/LibJS/JIT/NativeExecutable.cpp

@@ -43,11 +43,12 @@ void NativeExecutable::run(VM& vm, size_t entry_point) const
         VERIFY(entry_point_address != 0);
     }
 
-    typedef void (*JITCode)(VM&, Value* registers, Value* locals, FlatPtr entry_point_address);
+    typedef void (*JITCode)(VM&, Value* registers, Value* locals, FlatPtr entry_point_address, ExecutionContext&);
     ((JITCode)m_code)(vm,
         vm.bytecode_interpreter().registers().data(),
         vm.running_execution_context().local_variables.data(),
-        entry_point_address);
+        entry_point_address,
+        vm.running_execution_context());
 }
 
 #if ARCH(X86_64)