invoke.texi: Document the -fprofile-abs-path option.

invoke.texi: Document the -fprofile-abs-path option.

2017-06-05  Bernd Edlinger  <bernd.edlinger@hotmail.de>

        * doc/invoke.texi: Document the -fprofile-abs-path option.
        * common.opt (fprofile-abs-path): New option.
        * gcov-io.h (gcov_write_filename): Declare.
        * gcov-io.c (gcov_write_filename): New function.
        * coverage.c (coverage_begin_function): Use gcov_write_filename.
        * profile.c (output_location): Likewise.

gcc/testsuite:
2017-06-05  Bernd Edlinger  <bernd.edlinger@hotmail.de>

        * gcc.misc-tests/gcov-1a.c: New test.

From-SVN: r248894