erts: Fix spurious exceptions in 'fnegate'
erts: Fix spurious exceptions in 'fnegate'

If we were to enter an 'fnegate' instruction with a non-finite
value in xmm0 by accident, we would erroneously throw an
exception.

I'm not certain whether this can occur in practice: 'fnegate' is
always preceded by another floating-point instruction that either
leaves a valid value in xmm0 or throws an exception (`fconv`,
`fload`, `fadd`, etc).

I can't think of a valid instruction sequence that would cause it,
but we'll fix it anyway just in case.

dgud/otp,dgud/otp,rlipscombe/otp,g-andrade/otp,rlipscombe/otp,vinoski/otp,dumbbell/otp,isvilen/otp,dgud/otp,rlipscombe/otp,potatosalad/otp,jj1bdx/otp,potatosalad/otp,rlipscombe/otp,jj1bdx/otp,jj1bdx/otp,dumbbell/otp,bjorng/otp,rlipscombe/otp,emacsmirror/erlang,dumbbell/otp,g-andrade/otp,bjorng/otp,potatosalad/otp,dgud/otp,rlipscombe/otp,isvilen/otp,rlipscombe/otp,dumbbell/otp,emacsmirror/erlang,g-andrade/otp,isvilen/otp,mikpe/otp,erlang/otp,dgud/otp,dumbbell/otp,erlang/otp,isvilen/otp,potatosalad/otp,g-andrade/otp,g-andrade/otp,jj1bdx/otp,mikpe/otp,isvilen/otp,vinoski/otp,potatosalad/otp,emacsmirror/erlang,vinoski/otp,emacsmirror/erlang,potatosalad/otp,mikpe/otp,potatosalad/otp,bjorng/otp,erlang/otp,dumbbell/otp,bjorng/otp,mikpe/otp,emacsmirror/erlang,potatosalad/otp,vinoski/otp,jj1bdx/otp,dgud/otp,jj1bdx/otp,g-andrade/otp,potatosalad/otp,dgud/otp,emacsmirror/erlang,bjorng/otp,rlipscombe/otp,vinoski/otp,vinoski/otp,erlang/otp,erlang/otp,bjorng/otp,vinoski/otp,dgud/otp,bjorng/otp,bjorng/otp,isvilen/otp,erlang/otp,g-andrade/otp,isvilen/otp,erlang/otp,mikpe/otp,isvilen/otp,jj1bdx/otp,emacsmirror/erlang,emacsmirror/erlang,isvilen/otp,dgud/otp,jj1bdx/otp,vinoski/otp,erlang/otp,erlang/otp,isvilen/otp,emacsmirror/erlang,jj1bdx/otp,rlipscombe/otp,dumbbell/otp,g-andrade/otp,vinoski/otp,mikpe/otp,g-andrade/otp,mikpe/otp,erlang/otp,mikpe/otp,dgud/otp,g-andrade/otp,rlipscombe/otp,bjorng/otp,vinoski/otp,dumbbell/otp,jj1bdx/otp,bjorng/otp,emacsmirror/erlang,mikpe/otp,potatosalad/otp,dumbbell/otp,mikpe/otp,dumbbell/otp