Cgen: support typed_hvcat() calls
Cgen: support typed_hvcat() calls

The syntax arr = [a, ...] is converted to hvcat()
calls by the julia compiler. Now Cgen can allocate
the array and assign the values properly. This is used in quant benchmark.

IntelLabs/ParallelAccelerator.jl,JuliaPackageMirrors/ParallelAccelerator.jl,malekbr/julia-to-tiramisu