[X86] LLVM >= 17 generates call to `__extendhfsf2` for bitcast -> and -> bitcast

C++ code:

_Float16 fabsf16(_Float16 x) {
    return __builtin_bit_cast(
        _Float16,
        static_cast<unsigned short>(
            __builtin_bit_cast(unsigned short, x) & 0x7fff
        )
    );
}

IR:

define dso_local noundef half @fabsf16(_Float16)(half noundef %x) local_unnamed_addr {
entry:
  %0 = bitcast half %x to i16
  %1 = and i16 %0, 32767
  %2 = bitcast i16 %1 to half
  ret half %2
}

Clang 16 output assembly with -O3:

fabsf16(_Float16):
        pextrw  eax, xmm0, 0
        and     eax, 32767
        pinsrw  xmm0, eax, 0
        ret

Clang 17 output assembly with -O3:

.LCPI0_0:
        .long   0x7fffffff
        .long   0x7fffffff
        .long   0x7fffffff
        .long   0x7fffffff
fabsf16(_Float16):
        push    rax
        call    __extendhfsf2@PLT
        andps   xmm0, xmmword ptr [rip + .LCPI0_0]
        call    __truncsfhf2@PLT
        pop     rax
        ret

Related: #104869 (comment).

cc @arsenm @lntue