Come up with startswith function.

gcc/ada/ChangeLog:

	* gcc-interface/utils.c (def_builtin_1): Use startswith
	function instead of strncmp.

gcc/analyzer/ChangeLog:

	* sm-file.cc (is_file_using_fn_p): Use startswith
	function instead of strncmp.

gcc/ChangeLog:

	* builtins.c (is_builtin_name): Use startswith
	function instead of strncmp.
	* collect2.c (main): Likewise.
	(has_lto_section): Likewise.
	(scan_libraries): Likewise.
	* coverage.c (coverage_checksum_string): Likewise.
	(coverage_init): Likewise.
	* dwarf2out.c (is_cxx): Likewise.
	(gen_compile_unit_die): Likewise.
	* gcc-ar.c (main): Likewise.
	* gcc.c (init_spec): Likewise.
	(read_specs): Likewise.
	(execute): Likewise.
	(check_live_switch): Likewise.
	* genattrtab.c (write_attr_case): Likewise.
	(IS_ATTR_GROUP): Likewise.
	* gencfn-macros.c (main): Likewise.
	* gengtype.c (type_for_name): Likewise.
	(gen_rtx_next): Likewise.
	(get_file_langdir): Likewise.
	(write_local): Likewise.
	* genmatch.c (get_operator): Likewise.
	(get_operand_type): Likewise.
	(expr::gen_transform): Likewise.
	* genoutput.c (validate_optab_operands): Likewise.
	* incpath.c (add_sysroot_to_chain): Likewise.
	* langhooks.c (lang_GNU_C): Likewise.
	(lang_GNU_CXX): Likewise.
	(lang_GNU_Fortran): Likewise.
	(lang_GNU_OBJC): Likewise.
	* lto-wrapper.c (run_gcc): Likewise.
	* omp-general.c (omp_max_simt_vf): Likewise.
	* omp-low.c (omp_runtime_api_call): Likewise.
	* opts-common.c (parse_options_from_collect_gcc_options): Likewise.
	* read-rtl-function.c (function_reader::read_rtx_operand_r): Likewise.
	* real.c (real_from_string): Likewise.
	* selftest.c (assert_str_startswith): Likewise.
	* timevar.c (timer::validate_phases): Likewise.
	* tree.c (get_file_function_name): Likewise.
	* ubsan.c (ubsan_use_new_style_p): Likewise.
	* varasm.c (default_function_rodata_section): Likewise.
	(incorporeal_function_p): Likewise.
	(default_section_type_flags): Likewise.
	* system.h (startswith): Define startswith.

gcc/c-family/ChangeLog:

	* c-ada-spec.c (print_destructor): Use startswith
	function instead of strncmp.
	(dump_ada_declaration): Likewise.
	* c-common.c (disable_builtin_function): Likewise.
	(def_builtin_1): Likewise.
	* c-format.c (check_tokens): Likewise.
	(check_plain): Likewise.
	(convert_format_name_to_system_name): Likewise.

gcc/c/ChangeLog:

	* c-aux-info.c (affix_data_type): Use startswith
	function instead of strncmp.
	* c-typeck.c (build_function_call_vec): Likewise.
	* gimple-parser.c (c_parser_gimple_parse_bb_spec): Likewise.

gcc/cp/ChangeLog:

	* decl.c (duplicate_decls): Use startswith
	function instead of strncmp.
	(cxx_builtin_function): Likewise.
	(omp_declare_variant_finalize_one): Likewise.
	(grokfndecl): Likewise.
	* error.c (dump_decl_name): Likewise.
	* mangle.c (find_decomp_unqualified_name): Likewise.
	(write_guarded_var_name): Likewise.
	(decl_tls_wrapper_p): Likewise.
	* parser.c (cp_parser_simple_type_specifier): Likewise.
	(cp_parser_tx_qualifier_opt): Likewise.
	* pt.c (template_parm_object_p): Likewise.
	(dguide_name_p): Likewise.

gcc/d/ChangeLog:

	* d-builtins.cc (do_build_builtin_fn): Use startswith
	function instead of strncmp.
	* dmd/dinterpret.c (evaluateIfBuiltin): Likewise.
	* dmd/dmangle.c: Likewise.
	* dmd/hdrgen.c: Likewise.
	* dmd/identifier.c (Identifier::toHChars2): Likewise.

gcc/fortran/ChangeLog:

	* decl.c (variable_decl): Use startswith
	function instead of strncmp.
	(gfc_match_end): Likewise.
	* gfortran.h (gfc_str_startswith): Likewise.
	* module.c (load_omp_udrs): Likewise.
	(read_module): Likewise.
	* options.c (gfc_handle_runtime_check_option): Likewise.
	* primary.c (match_arg_list_function): Likewise.
	* trans-decl.c (gfc_get_symbol_decl): Likewise.
	* trans-expr.c (gfc_conv_procedure_call): Likewise.
	* trans-intrinsic.c (gfc_conv_ieee_arithmetic_function): Likewise.

gcc/go/ChangeLog:

	* gofrontend/runtime.cc (Runtime::name_to_code): Use startswith
	function instead of strncmp.

gcc/objc/ChangeLog:

	* objc-act.c (objc_string_ref_type_p): Use startswith
	function instead of strncmp.
	* objc-encoding.c (encode_type): Likewise.
	* objc-next-runtime-abi-02.c (has_load_impl): Likewise.