Strictly speaking, according to Stallman himself compilers do not affect the license of binary produced by a compiler. However, the the C library, that you usually incorporate, that is GPL, it would make the whole binary GPL, if it were not for the GPL exception used.
I wander what would be true for Julia code (that wouldn't at least use the GPL parts of Julia). Yes, you are using Julia in the same process, but would that mean all source code of yours would be automatically derived software of Julia? That would make all Julia code GPL.. and doesn't seem to make sense (any more than, Linux programs, derived software of the Linux kernel, but it has an explicit, notice to that effect, mostly so people to not assume that?)
Maybe as Julia is unusual, has macros/metaprogramming, Julia should not be considered as a generic compiler.. same argument should be made as for any Lisp-compiler/system.