i386: Fix up types in __builtin_{inf,huge_val,nan{,s},fabs,copysign}q builtins [PR109884]

When _Float128 support has been added to C++ for 13.1,  float128t_type_node
tree has been added - in C float128_type_node and float128t_type_node is
the same and represents both _Float128 and __float128, but in C++ they
are distinct types which have different handling in the FEs.
When doing that change, I mistakenly forgot to change FLOAT128 primitive
type, which is used for the __builtin_{inf,huge_val,nan{,s},fabs,copysign}q
builtins results and some of their arguments (and nothing else).

The following patch fixes that.
On ia64 we already use float128t_type_node for those builtins, pa while
it has __float128 that type is the same as long double and so those builtins
have long double types and on powerpc seems we  don't have these builtins
but instead define macros which map them to __builtin_*f128.  That will
not work properly in C++, perhaps we should change those macros to be
function-like and cast to __float128.

2023-05-17  Jakub Jelinek  <jakub@redhat.com>

	PR c++/109884
	* config/i386/i386-builtin-types.def (FLOAT128): Use
	float128t_type_node rather than float128_type_node.

	* c-c++-common/pr109884.c: New test.

(cherry picked from commit c8da62cf)