Added precondition inline.  Starting the process of getting constraints checked at runtime again.
Added precondition inline.  Starting the process of getting constraints checked at runtime again.

hjwylde/whiley-compiler,hjwylde/whiley-compiler,hjwylde/whiley-compiler,hjwylde/whiley-compiler,hjwylde/whiley-compiler,Whiley/WhileyCompiler