[flang][OpenMP] runtime segfault when an allocatable variable is used with copyin

[tblah]

program foo
  real, allocatable :: ra
  !$omp threadprivate(ra)
  allocate(ra)
  ra = 10
  !$omp parallel num_threads(2) copyin(ra)
  print *,ra
  !$omp end parallel
end program

Compiling with flang -fopenmp version 8e6abf52e7 gives a segfault in the compiled aplication after the print.

CC @DavidTruby

[llvmbot]

@llvm/issue-subscribers-flang-ir

Author: Tom Eccles (tblah)

``` program foo real, allocatable :: ra !$omp threadprivate(ra) allocate(ra) ra = 10 !$omp parallel num_threads(2) copyin(ra) print *,ra !$omp end parallel end program ```

Compiling with flang -fopenmp version 8e6abf52e7 gives a segfault in the compiled aplication after the print.

CC @DavidTruby