Add {symbol,call}_summary::get method and use it in HSA.

Add {symbol,call}_summary::get method and use it in HSA.

2018-06-08  Martin Liska  <mliska@suse.cz>

	* hsa-common.h (enum hsa_function_kind): Rename HSA_NONE to
	HSA_INVALID.
	(hsa_function_summary::hsa_function_summary): Use the new enum
	value.
	(hsa_gpu_implementation_p): Use hsa_summaries::get.
	* hsa-gen.c (hsa_get_host_function): Likewise.
	(get_brig_function_name): Likewise.
	* ipa-hsa.c (process_hsa_functions): Likewise.
	(ipa_hsa_write_summary): Likewise.
	* symbol-summary.h (symtab_duplication): Use ::get function/
	(get): New function.

From-SVN: r261310