Add a FAQ entry about the names of openmp offloading components
and how they are searched for.

Reviewed By: jhuber6

Differential Revision: https://reviews.llvm.org/D109619

Summary:
Change the name for targeting AMD offloading.

This patch adds documentation for using the CMake find module for OpenMP
target offloading provided by LLVM. It also removes the requirement for
AMD's architecture to be set as this isn't necessary for upstream LLVM.

Reviewed By: jdoerfert

Differential Revision: https://reviews.llvm.org/D105051

Add an FAQ entry and add a few lines to an existing one. Document
the use of `GCC_INSTALL_PREFIX` for pointing clang to correct
GCC installation for two-stage build.

Reviewed By: jhuber6

Differential Revision: https://reviews.llvm.org/D104474

[libomptarget] Initial documentation on amdgpu offload

Reviewed By: jdoerfert

Differential Revision: https://reviews.llvm.org/D101927

Summary:
Add an FAW entry detailing the support for using dynamically linked libraries
with OpenMP Offloading

This introduces a remote offloading plugin for libomptarget. This
implementation relies on gRPC and protobuf, so this library will only
build if both libraries are available on the system. The corresponding
server is compiled to `openmp-offloading-server`.

This is a large change, but the only way to split this up is into RTL/server
but I fear that could introduce an inconsistency amongst them.

Ideally, tests for this should be added to the current ones that but that is
problematic for at least one reason. Given that libomptarget registers plugin
on a first-come-first-serve basis, if we wanted to offload onto a local x86
through a different process, then we'd have to either re-order the plugin list
in `rtl.cpp` (which is what I did locally for testing) or find a better
solution for runtime plugin registration in libomptarget.

Differential Revision: https://reviews.llvm.org/D95314