[analyzer] Equality ops are like relational ops in that the arguments...

[analyzer] Equality ops are like relational ops in that the arguments shouldn't be converted to the result type. Fixes PR12206 and dupe PR12510.

This was probably the original intent of r133041 (also me, a year ago).

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@156062 91177308-0d34-0410-b5e6-96231b3b80d8