[Bug rtl-optimization/101044] -ABS(A) produces two neg instructions

[ubizjak at gmail dot com]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=101044

--- Comment #3 from Uroš Bizjak <ubizjak at gmail dot com> ---
The compound nabs insn also needs to be handled in the STV pass.