[Bug target/104580] [nvptx] Use prevent_branch_around_nothing only when necessary

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

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=104580

--- Comment #1 from Tom de Vries <vries at gcc dot gnu.org> ---
Created attachment 52457
  --> https://gcc.gnu.org/bugzilla/attachment.cgi?id=52457&action=edit
Tentative patch