* Makefile.in (ORDINARY_FLAGS_TO_PASS): Also pass DESTDIR.
	(install-gcc-tooldir, install-cpp, installdirs,
	install-common, install-driver, install-info, install-man,
	install-headers, install-include-dir, install-headers-tar,
	install-headers-cpio, install-headers-cp, install-mkheaders,
	install-collect2, uninstall): Prepend $(DESTDIR) to
	destination paths in all (un)installation commands.
	(install-driver): Rewrite $(LN) commands to support DESTDIR
	with "ln" as well as with "ln -s".
	(installdirs): Simply use mkinstalldirs.
	(install-libgcc, install-multilib): Also pass DESTDIR.
	* mklibgcc.in: Prepend $(DESTDIR) to $(libsubdir) in the
	installation destination variable ldir.
	* config/alpha/t-osf4, config/arm/t-netbsd,
	config/ia64/t-hpux, config/mips/t-iris5-6,
	config/pa/t-hpux-shlib, config/rs6000/t-aix43,
	config/rs6000/t-aix52, config/t-slibgcc-elf-ver,
	config/t-slibgcc-sld: Prepend $$(DESTDIR) to $$(slibdir)
	in the definition of SHLIB_INSTALL.
	* config/arc/t-arc (install-multilib-arc): Prepend $(DESTDIR) to
	$(libsubdir) in the installation commands.

From-SVN: r61076