[compiler-rt] [builtins] Avoid using long double in FreeBSD standalone environment (PR #76175)

[Dimitry Andric via llvm-commits]

DimitryAndric wrote:

> The _tf functions are not long double, they are tetra-float, i.e. 128-bit floating point. Using long double was incorrect for x86 which should only be using it for the xf_ functions. So you should remove the xf files for !x86.
> 
> The other option would be to use the same pattern as in the tf files where they compile to nothing if 80-bit floats are not available (this would require updating the ifdef guards and is probably a bit more work than just changing the makefile).

Yes, I've done this in https://github.com/DimitryAndric/freebsd-src/commit/2d203488be4243b3b3f38835dfe68122ea9a1ca5 , effectively moving `divxc3` and friends to 80-bit x86-only, and `divtc3` and friends to the 128-bit quad section.


https://github.com/llvm/llvm-project/pull/76175