* gcov-io.h (GCOV_LOCKED): New #define.
	(GCOV_LINKAGE): Make sure it is #defined.
	(gcov_write_string, gcov_write_tag, gcov_write_length,
	gcov_read_string, gcov_time): Poison in libgcov.
	(gcov_seek_end): Remove.
	(gcov_write_tag_length, gcov_sync, gcov_rewrite): New.
	(GCOV_TAG_FUNCTION_LENGTH, GCOV_TAG_BLOCKS_LENGTH,
	GCOV_TAG_ARCS_LENGTH, GCOV_TAG_COUNTER_LENGTH,
	GCOV_TAG_SUMMARY_LENGTH): New #defines.
	(gcov_write_tag, gcov_write_length): Not in libgcov.
	* gcov-io.c (gcov_open): Use GCOV_LOCKED.
	(gcov_write_tag, gcov_write_length): Not in libgcov.
	(gcov_write_tag_length): New.
	(gcov_write_summary): Use gcov_write_tag_length.
	* libgcov.c: Always #include gcov-io.h.
	(IN_LIBGCOV): -1 for inhibit_libc, +1 otherwise.
	(GCOV_LINKAGE): Define to nothing for L_gcov.
	(gcov_exit): Replace gcov_write_tag, gcov_write_length with
	gcov_write_tag_length. Use gcov_rewrite & gcov_seek.
	* gcov.c (read_graph_file): Replace gcov_seek by gcov_sync.
	(read_count_file): Likewise.
	* gcov-dump.c (dump_file): Likewise.
	* coverag.c (read_counts_file): Likewise.

From-SVN: r66555