c++, libstdc++: Add typeinfo for _Float{16,32,64,128,32x,64x} and __bf16 types [PR108075]

c++, libstdc++: Add typeinfo for _Float{16,32,64,128,32x,64x} and __bf16 types [PR108075]

The following patch adds typeinfos for the extended floating point
types and _Float{32,64}x.

2022-12-15  Jakub Jelinek  <jakub@redhat.com>

	PR libstdc++/108075
gcc/cp/
	* rtti.cc (emit_support_tinfos): Add pointers to
	{bfloat16,float{16,32,64,128,32x,64x,128x}}_type_node to fundamentals
	array.
gcc/testsuite/
	* g++.dg/cpp23/ext-floating13.C: New test.
libstdc++-v3/
	* config/abi/pre/gnu.ver (CXXABI_1.3.14): Export
	_ZTIDF[0-9]*[_bx], _ZTIPDF[0-9]*[_bx] and _ZTIPKDF[0-9]*[_bx].
	* testsuite/util/testsuite_abi.cc (check_version): Handle
	CXXABI_1.3.14.