Rework be15dfa8 such that it works with GlobalISel which doesn't use EVT

Summary:
be15dfa8 broke GlobalISel's usage of getSetCCInverse() which currently
appears to be limited to our out-of-tree backend. GlobalISel doesn't use
EVT's and isn't able to derive them from the information it has as it
doesn't distinguish between integer and floating point types (that
distinction is made by operations rather than values). Bring back the
bool version of getSetCCInverse() in a way that doesn't break the intent
of be15dfa8 but also allows GlobalISel to continue using it.

Reviewers: spatel, bogner, arichardson

Reviewed By: arichardson

Subscribers: rovka, hiraditya, Petar.Avramovic, llvm-commits

Tags: #llvm

Differential Revision: https://reviews.llvm.org/D72309