Include: Sync lto-symtab.h and plugin-api.h with GCC

2020-03-19  Martin Liska  <mliska@suse.cz>

	* lto-symtab.h (enum gcc_plugin_symbol_type): New.
	(enum gcc_plugin_symbol_section_kind): Likewise.

2020-03-19  Martin Liska  <mliska@suse.cz>

	* plugin-api.h (struct ld_plugin_symbol): Split
	int def into 4 char fields.
	(enum ld_plugin_symbol_type): New.
	(enum ld_plugin_symbol_section_kind): New.
	(enum ld_plugin_tag): Add LDPT_ADD_SYMBOLS_V2.

(cherry picked from commit 3734bec8)