PR jit/63854: Fix leak within jit-builtins.c

PR jit/63854: Fix leak within jit-builtins.c

gcc/jit/ChangeLog:
	PR jit/63854
	* jit-builtins.c
	(gcc::jit::recording::builtins_manager::make_fn_type): Call the
	context's new_function_type method, rather than directly creating
	a function_type instance.
	* jit-recording.c
	(gcc::jit::recording::context::new_function_type): New method,
	adapted from part of...
	(gcc::jit::recording::context::new_function_ptr_type): ...this.
	Update to call new_function_type.
	* jit-recording.h
	(gcc::jit::recording::context::new_function_type): New method.

From-SVN: r218231