Don't include codeconv files (#662)

* Don't include codeconv files

* Update setup.jl

Author: wsmoses

test/setup.jl

@@ -5,7 +5,7 @@ using SPIRV_LLVM_Translator_unified_jll, SPIRV_Tools_jll
 # include all helpers
 include(joinpath(@__DIR__, "helpers", "runtime.jl"))
 for file in readdir(joinpath(@__DIR__, "helpers"))
-    if file != "runtime.jl"
+    if endswith(file, ".jl") && file != "runtime.jl"
         include(joinpath(@__DIR__, "helpers", file))
     end
 end