Remove alpha specific fmax, fmin to fix sNaN handling [BZ #22660]

Remove alpha specific fmax, fmin to fix sNaN handling [BZ #22660]

Various fmax and fmin function implementations mishandle sNaN
arguments:

(a) When both arguments are NaNs, the return value should be a qNaN,
but sometimes it is an sNaN if at least one argument is an sNaN.

(b) Under TS 18661-1 semantics, if either argument is an sNaN then the
result should be a qNaN (whereas if one argument is a qNaN and the
other is not a NaN, the result should be the non-NaN argument).
Various implementations treat sNaNs like qNaNs here.

One way to fix that is to detect the sNaN and add a special case. That
said there is no FPU instruction to do that, so it requires transfering
the FP value to an integer register and testing bits. This becomes quite
complicated so it's probably better to just use the generic versions of
these functions which just do that through issignaling.

Changelog:
	[BZ #22660]
	* sysdeps/alpha/fpu/s_fmax.S: Remove file.
	* sysdeps/alpha/fpu/s_fmaxf.S: Likewise.
	* sysdeps/alpha/fpu/s_fmin.S: Likewise.
	* sysdeps/alpha/fpu/s_fminf.S: Likewise.