Missing cdefs-compat.h

[ViralBShah]

On a fresh checkout on ubuntu 14.04, using gcc 4.8, I am seeing:

In file included from /home/justdial/julia/usr/include/openlibm.h:4:0,
                 from Faddeeva/Faddeeva.cc:225,
                 from Faddeeva/Faddeeva.c:3:
/home/justdial/julia/usr/include/openlibm_complex.h:27:0: warning: "_Complex_I" redefined [enabled by default]
 #define _Complex_I 1.0fi
 ^
In file included from Faddeeva/Faddeeva.h:31:0,
                 from Faddeeva/Faddeeva.cc:218,
                 from Faddeeva/Faddeeva.c:3:
/usr/include/complex.h:44:0: note: this is the location of the previous definition
 #define _Complex_I (__extension__ 1.0iF)
 ^
In file included from /home/justdial/julia/usr/include/openlibm_fenv.h:8:0,
                 from /home/justdial/julia/usr/include/openlibm.h:5,
                 from Faddeeva/Faddeeva.cc:225,
                 from Faddeeva/Faddeeva.c:3:
/home/justdial/julia/usr/include/openlibm_fenv_amd64.h:32:26: fatal error: cdefs-compat.h: No such file or directory
 #include "cdefs-compat.h"
                          ^

[ViralBShah]

I believe this was a make -j artefact, and the build had got into a weird state.