Fix tfunc tables for fptoui and fptosi

[timholy]

While working on an interpreter (JuliaDebug/ASTInterpreter2.jl#37) I noticed that fptoui and fptosi only support the 2-argument form:

julia> f(x) = Base.fptoui(x)
f (generic function with 1 method)

julia> f(3.0)
ERROR: error compiling f: intrinsic #55 fptoui: wrong number of arguments
Stacktrace:
 [1] top-level scope at REPL[2]:1

However, the 1-argument form is still present in inference's tfunc tables. I'm going to mark this for backporting since that behavior seems present even on 0.7. But this is very low priority, I am not aware of anything other than JuliaDebug/ASTInterpreter2.jl#37 that needs this (and there I have a workaround).

[vtjnash]

Yep, 2-arg should be deprecated, so this is just a theoretical memory improvement (it'll delete more dead code after the error was thrown), with no actual impact.

[timholy]

2-arg should be deprecated

You mean 1-arg, right?