[flang] preserve logical operations in single FIR operation (#190771)
This patch adds new operations to represent AND/OR/EQV/NEQV logical
operation with the main goal of preserving them at a higher level in the
IR to make it easier to match them and to dispatch them to atomic
implementations when working on reductions.
They are only generated when one of the argument is actually a logical,
otherwise, the when dealing with AND/OR... where both operands are
comparisons, the i1 arith operations are still generated since using the
new operation would make the IR more complex and preserving logical
operation is only valuable when one of the operand is a logical
variable.