[mlir][llvm] Handle invoke op branching to block with its result as an argument

In LLVM, having an invoke instruction branching to a block with a phi
node receiving the invoke instruction result as an argument is
perfectly legal. However, the translation of this construct to MLIR
would result in an invoke with its result being used as a block
argument to a successor, i.e., the operation result would be used in
its definition.

In order to fix this issue due to different IR structures (phi nodes
vs block arguments), this construct is interpreted with an llvm.invoke
operation branching to a dummy block having a single llvm.br operation
passing the required block arguments (including the result of the
llvm.invoke operation) to the actual successor block.

Differential Revision: https://reviews.llvm.org/D148313