* configure.in (enable_coverage): New enable switch.
	* configure: Rebuilt.
	* Makefile.in (COVERAGE_FLAGS, coverageexts): New variables.
	(INTERNAL_CFLAGS): Append COVERAGE_FLAGS.
	(ALL_FLAGS): Reorder so INTERNAL_CFLAGS comes after CFLAGS.
	(mostlyclean): Remove coverage files.
	* doc/install.texi: Document enable_coverage.

	* cp/Make-lang.in (c++.mostlyclean): Remove coverage files.
	* ada/Make-lang.in (ada.mostlyclean): Remove coverage files.
	* f/Make-lang.in (f.mostlyclean): Remove coverage files.
	* java/Make-lang.in (java.mostlyclean): Remove coverage files.
	* objc/Make-lang.in (objc.mostlyclean): Remove coverage files.
	* treelang/Make-lang.in (treelang.mostlyclean): Remove coverage
	files.

From-SVN: r56126