Harden the expression evaluation
Harden the expression evaluation

Intended to catch more errors, including in the F# Compiler itself.
Doing this mainly for Mono issue where we're getting silent failures.

#143

BayardRock/IfSharp,npmurphy/IfSharp,BayardRock/IfSharp,npmurphy/IfSharp,BayardRock/IfSharp,npmurphy/IfSharp,BayardRock/IfSharp,npmurphy/IfSharp