This fixes PR gcov-profile/54487 where the gcda files were not locked
by the profile-use read, enabling writes by other instrumented compiles
to change the profile in the middle of the profile use read. The GCOV_LOCKED
macro was not set because it was guarded by HOST_HAS_F_SETLKW, which was
never set. The fix is to add a compile test in the configure to set it.

2012-09-12  Teresa Johnson  <tejohnson@google.com>

	PR gcov-profile/54487
	* configure.ac (HOST_HAS_F_SETLKW): Set based on compile
	test using F_SETLKW with fcntl.
	* configure, config.in: Regenerate.

From-SVN: r191238