[Flang][OpenMP] Add lowering from PFT to new MapEntry and Bounds operations...

[Flang][OpenMP] Add lowering from PFT to new MapEntry and Bounds operations and tie them to relevant Target operations

This patch builds on top of a prior patch in review which adds a new map
and bounds operation by modifying the OpenMP PFT lowering to support
these operations and generate them from the PFT.

A significant amount of the support for the Bounds operation is borrowed
from OpenACC's own current implementation and lowering, just ported
over to OpenMP.

The patch also adds very preliminary/initial support for lowering to
a new Capture attribute, which is stored on the new Map Operation,
which helps the later lowering from OpenMP -> LLVM IR by indicating
how a map argument should be handled. This capture type will
influence how a map argument is accessed on device and passed by
the host (different load/store handling etc.). It is reflective of a
similar piece of information stored in the Clang AST which performs a
similar role.

As well as some minor adjustments to how the map type (map bitshift
which dictates to the runtime how it should handle an argument) is
generated to further support more use-cases for future patches that
build on this work.

Finally it adds the map entry operation creation and tying it to the relevant
target operations as well as the addition of some new tests and alteration
of previous tests to support the new changes.

Depends on D158732

reviewers: kiranchandramohan, TIFitis, clementval, razvanlupusoru

Differential Revision: https://reviews.llvm.org/D158734