Fix segmentation fault when `Module#name` returns non string value
	 [Bug #17754]

	* Add test for NoMethodError#to_s does not segfault

	* Ensure no segfault even if Module#name is overridden
	---
	 error.c                          |  4 +++-
	 test/ruby/test_nomethod_error.rb | 16 ++++++++++++++++
	 2 files changed, 19 insertions(+), 1 deletion(-)