PR lto/86004
	* doc/sourcebuild.texi (lto_incremental): Document new effective
	target.

	* lib/target-supports.exp (check_effective_target_lto_incremental):
	New.
	* g++.dg/lto/pr69137_0.C: Require lto_incremental effective target.
	* g++.dg/lto/pr65316_0.C: Likewise.
	* g++.dg/lto/pr85176_0.C: Likewise.
	* g++.dg/lto/pr79000_0.C: Likewise.
	* g++.dg/lto/pr66180_0.C: Likewise.
	* g++.dg/lto/pr65193_0.C: Likewise.
	* g++.dg/lto/pr69077_0.C: Likewise.
	* g++.dg/lto/pr68057_0.C: Likewise.
	* g++.dg/lto/pr66705_0.C: Likewise.
	* g++.dg/lto/pr65302_0.C: Likewise.
	* g++.dg/lto/20091002-1_0.C: Likewise.
	* g++.dg/lto/pr81940_0.C: Likewise.
	* g++.dg/lto/pr64043_0.C: Likewise.
	* g++.dg/lto/pr65549_0.C: Likewise.
	* g++.dg/lto/pr69133_0.C: Likewise.
	* gfortran.dg/lto/pr79108_0.f90: Likewise.

From-SVN: r266974