[Bug target/112306] [AArch64][neon] incorrect combine the (a -1)* b into fnmsub for fixed vector type

[pinskia at gcc dot gnu.org via Gcc-bugs]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=112306

--- Comment #3 from Andrew Pinski <pinskia at gcc dot gnu.org> ---
Using:
#include <arm_neon.h>

instead of the manually (incorrect) definition of float32x4_t, GCC produces:
test2_float_vec:
        fneg    v31.4s, v1.4s
        fmla    v31.4s, v0.4s, v1.4s
        mov     v0.16b, v31.16b
        ret