[binutils-gdb] Make tdesc_feature::name an std::string

[sergiodj+buildbot at sergiodj dot net]

*** TEST RESULTS FOR COMMIT f65ff9f9a4add415e5ae332a094b2134c1625517 ***

Author: Simon Marchi <simon.marchi@polymtl.ca>
Branch: master
Commit: f65ff9f9a4add415e5ae332a094b2134c1625517

Make tdesc_feature::name an std::string

... so we don't have to manually free it in ~tdesc_feature.

gdb/ChangeLog:

	* target-descriptions.c (tdesc_feature) <name>: Change type to
	std::string.
	<~tdesc_feature>: Don't manually free name.
	<operator==>: Adjust.
	(tdesc_find_feature): Adjust.
	(tdesc_feature_name): Adjust.
	(class print_c_tdesc) <visit_pre>: Adjust.
	(class print_c_feature) <visit_pre>: Adjust.