[flang] Add co_sum to the list of intrinsics and update test

[flang] Add co_sum to the list of intrinsics and update test

Add the collective subroutine, co_sum, to the list of intrinsics.
In accordance with 16.9.50 and 16.9.137, add a check for and an
error if coindexed objects are being passed to certain arguments
in co_sum and in move_alloc. Add a semantics test to check that
this error is successfully caught in calls to move_alloc. Remove
the XFAIL directive, update the ERROR directives and add both
standard-conforming and non-standard conforming calls to the
semantics test for co_sum.

Reviewed By: jeanPerier

Differential Revision: https://reviews.llvm.org/D114134