Assignment to unallocated arrays fails in flang

[aprokop]

   ! FIXME: without these allocation, the test segfaults when compiled with flang
    ! According to [this](https://stackoverflow.com/questions/42140832/automatic-array-allocation-upon-assignment-in-fortran) it
    ! seems that it should be supported in F2003. So it is not clear why flang fails.
    allocate(iarr(10))
    allocate(darr(10))
    iarr = plist%get_arr_integer('intarr')

[sethrj]

Interesting, I wonder if this is related to the -Wmaybe-uninitialized warning that shows up in GCC when returning an allocatable string.