LibJS: Inline JS-to-JS calls in the bytecode interpreter dispatch loop

Instead of recursing through 5 native stack frames per JS function
call (execute_call -> internal_call -> ordinary_call_evaluate_body ->
run_executable -> run_bytecode), handle Call and CallConstruct for
normal ECMAScript functions directly in the dispatch loop.

The fast path allocates the callee's execution context on the
InterpreterStack, copies arguments, sets up the environment, and
jumps to the callee's bytecode entry point. Return and End unwind
inline frames by restoring the caller's state. Exception unwinding
walks through inline frames to find handlers.

The fast path code is kept in NEVER_INLINE helper functions
(try_inline_call, try_inline_call_construct, pop_inline_frame) to
minimize register pressure in the dispatch loop. handle_exception
takes program_counter by value to avoid forcing it onto the stack.
Reloading of bytecode/program_counter after frame switches is done
inline at each call site via RELOAD_AND_GOTO_START to preserve a
single dispatch entry point for optimal indirect branch prediction.

Libraries/LibJS/Runtime/ECMAScriptFunctionObject.h

@@ -121,6 +121,7 @@ public:
     bool allocates_function_environment() const { return shared_data().m_function_environment_needed; }
 
     friend class Bytecode::Generator;
+    friend class Bytecode::Interpreter;
 
 private:
     ECMAScriptFunctionObject(