Make functions in `numeric.md` total `functional`

Right now there are #Ceil side-condition generated by the backend for the operators defined in numeric.md:

    syntax Val ::= IValType "." IUnOp Int   [klabel(intUnOp)  , function] 
                 | FValType "." FUnOp Float [klabel(floatUnOp), function] 
 // --------------------------------------------------------------------- 
    syntax Val ::= IValType "." IBinOp Int   Int   [klabel(intBinOp)  , function] 
                 | FValType "." FBinOp Float Float [klabel(floatBinOp), function] 
 // ----------------------------------------------------------------------------- 
    syntax Val ::= IValType "." TestOp Int [klabel(intTestOp), function] 
 // -------------------------------------------------------------------- 
    syntax Val ::= IValType "." IRelOp Int   Int   [klabel(intRelOp)  , function] 
                 | FValType "." FRelOp Float Float [klabel(floatRelOp), function] 
 // ----------------------------------------------------------------------------- 
    syntax Val ::= AValType "." CvtOp Number [klabel(numberCvtOp), function] 
 // ------------------------------------------------------------------------ 

I'm pretty sure these all can be made functional, with the appropriate changes to the helper functions they use.

For example:

• The functions #minWidth, #ctz, #popcnt, #round, #signed, #unsigned, #isInfinityOrNan, and truncFloat need to be made total.
• rule FTYPE . sqrt => ... needs to either have (i) sqrtFloat be made functional in domains.k, or (ii) explicitely handle the cases that sqrtFloat does not.

Start in numeric.md, reviewing the listed operator definitions and helper functions such as #minWidth, #ctz, #popcnt, #round, #signed, #unsigned, #isInfinityOrNan, and truncFloat. Then inspect domains.k for sqrtFloat and determine whether it can be made functional or whether sqrt's unsupported cases need explicit handling; done means the operators no longer generate #Ceil side conditions.