P0806R2 - Deprecate implicit capture of this via [=]
	* lambda.c (add_default_capture): Formatting fixes.  Warn about
	deprecated implicit capture of this via [=].

	* g++.dg/cpp2a/lambda-this1.C: New test.
	* g++.dg/cpp2a/lambda-this2.C: New test.
	* g++.dg/cpp2a/lambda-this3.C: New test.

From-SVN: r263508