Exception for math.abs on complex

Math

\[\sqrt{re \cdot re + im \cdot im}\]

C

double f(double re, double im) {
        double r38271 = re;
        double r38272 = r38271 * r38271;
        double r38273 = im;
        double r38274 = r38273 * r38273;
        double r38275 = r38272 + r38274;
        double r38276 = sqrt(r38275);
        return r38276;
}

Reproduce

Please include this information when filing a bug report:

herbie shell --seed 2019323 
(FPCore (re im)
  :name "math.abs on complex"
  :precision binary64
  (sqrt (+ (* re re) (* im im))))

Backtrace

get-representation: Unknown representation real		L	C
(unnamed)	/data/pavpan/nightlies/herbie/fix-interface-bugs/src/core/regimes.rkt	65	3
filter	/opt/racket-7.2/collects/racket/private/list.rkt	256	2
infer-splitpoints	/data/pavpan/nightlies/herbie/fix-interface-bugs/src/core/regimes.rkt	34	0
get-final-combination	/data/pavpan/nightlies/herbie/fix-interface-bugs/src/mainloop.rkt	369	0
(unnamed)	/opt/racket-7.2/collects/racket/private/more-scheme.rkt	261	28
run	/opt/racket-7.2/share/pkgs/profile-lib/main.rkt	39	2
profile-thunk16	/opt/racket-7.2/share/pkgs/profile-lib/main.rkt	9	0
(unnamed)	/opt/racket-7.2/collects/racket/private/more-scheme.rkt	261	28