PR other/43838

	PR other/43838
	* cp-demangle.c (struct d_print_info): Add flush_count field.
	(d_print_init): Initialize it to 0.
	(d_print_flush): Increment it.
	(d_print_comp): If needed flush before appending ", ".  Only
	decrement dpi->len if no flushes happened during the recursive
	call.
	* testsuite/demangle-expected: Add a test for this.