lto-wrapper.c (compile_offload_image): Start processing in_argv from 0 instead of 1.

gcc/
	* lto-wrapper.c (compile_offload_image): Start processing in_argv
	from 0 instead of 1.
	(run_gcc): Put offload objects into offload_argv, put LTO objects and
	possible preceding arguments into lto_argv.
	Pass offload_argv to compile_images_for_offload_targets instead of argv.
	Use lto_argv for LTO recompilation instead of argv.
lto-plugin/
	* lto-plugin.c (offload_files, num_offload_files): New static variables.
	(free_1): Use arguments instead of global variables.
	(free_2): Free offload_files.
	(all_symbols_read_handler): Add names from offload_files to lto-wrapper
	arguments.
	(claim_file_handler): Do not add file to claimed_files if it contains
	offload sections without LTO sections.  Add it to offload_files instead.

From-SVN: r218543