Add a comment that describes tryEvaluate.  Make tryEvaluate fold
__builtin_constant_p properly, and add some scaffolding for
FloatExprEvaluator to eventually handle huge_val and inf.



git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@57152 91177308-0d34-0410-b5e6-96231b3b80d8
3 files changed