[Bug rtl-optimization/115876] [15 regression] ext-dce.cc has ubsan issues; shifting negative values

[jamborm at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=115876

--- Comment #11 from Martin Jambor <jamborm at gcc dot gnu.org> ---
Our weekend ubsan bootstrap and test (of revision
r15-2173-ge0d997e913f811) still reported failures when compiling
testcase gfortran.dg/ieee/large_1.f90 (at -O2 and higher).