coverage.c (bbg_file_stamp): New.
* coverage.c (bbg_file_stamp): New.
(read_counts_file): Merge incoming stamp with bbg_file_stamp.
(build_info): Write bbg_file_stamp.
(coverage_init): Initialize bbg_file_stamp. Read counts file
before writing graph header.
(coverage_finish): Don't unlink the data file if we can generate a
unique file stamp.
* tree.h (crc32_unsigned): Declare.
* tree.c (crc32_unsigned_bits): New, broken out of ...
(crc32_byte): ... here. Use it.
(crc32_unsigned): New.
From-SVN: r189095