acinclude.m4 (GLIBCXX_ENABLE_SYMVERS): Bump minimal version requirement.

2003-07-05  Phil Edwards  <pme@gcc.gnu.org>

	* acinclude.m4 (GLIBCXX_ENABLE_SYMVERS):  Bump minimal version
	requirement.  Add port_specific_symbol_file variable.
	* configure.host:  Add docs for port_specific_symbol_file.
	Clean up try_cpu block for x86.
	* config/linker-map.gnu:  No more "last symbol can't have a
	semicolon" kaka.  Add hook for port-specific symbols.
	* src/Makefile.am:  Remove trailing whitespace.
	(libstdc++-symbol.ver):  Detect the presence of port-specific
	symbols, and add them accordingly.

	* docs/html/17_intro/porting.texi:  Bring up to date.

	* src/Makefile.in, aclocal.m4, configure,
	docs/html/17_intro/porting.html:  Regenerated.

From-SVN: r68992