[OpenMPIRBuilder][Clang][NFC] - Combine emitOffloadingArrays and emitOffloadingArraysArgument in OpenMPIRBuilder

[bhandarkar-pranav]

This PR introduces a new interface in OpenMPIRBuilder that combines the creation of the so-called offloading pointer arrays and their subsequent preparation as arguments to the OpenMP runtime library. We then use this in Clang. This is intended to be used in the near future by other frontends such as Flang when lowering MLIR to LLVMIR.

[jsjodin]

One nit, otherwise LGTM.

[github-actions]

✅ With the latest revision this PR passed the C/C++ code formatter.

[llvm-ci]

LLVM Buildbot has detected a new failure on builder llvm-clang-aarch64-darwin running on doug-worker-5 while building clang,llvm at step 6 "test-build-unified-tree-check-all".

Full details are available at: https://lab.llvm.org/buildbot/#/builders/190/builds/2675

Here is the relevant piece of the build log for the reference:

Step 6 (test-build-unified-tree-check-all) failure: test (failure)
******************** TEST 'Clang Tools :: clang-doc/basic-project.test' FAILED ********************
Exit Code: 1

Command Output (stdout):
--
Emiting docs in html format.
Mapping decls...
Collecting infos...
Reducing 5 infos...
Generating docs...
Generating assets for docs...

--
Command Output (stderr):
--
RUN: at line 1: rm -rf /Users/buildbot/buildbot-root/aarch64-darwin/build/tools/clang/tools/extra/test/clang-doc/Output/basic-project.test.tmp && mkdir -p /Users/buildbot/buildbot-root/aarch64-darwin/build/tools/clang/tools/extra/test/clang-doc/Output/basic-project.test.tmp/docs /Users/buildbot/buildbot-root/aarch64-darwin/build/tools/clang/tools/extra/test/clang-doc/Output/basic-project.test.tmp/build
+ rm -rf /Users/buildbot/buildbot-root/aarch64-darwin/build/tools/clang/tools/extra/test/clang-doc/Output/basic-project.test.tmp
+ mkdir -p /Users/buildbot/buildbot-root/aarch64-darwin/build/tools/clang/tools/extra/test/clang-doc/Output/basic-project.test.tmp/docs /Users/buildbot/buildbot-root/aarch64-darwin/build/tools/clang/tools/extra/test/clang-doc/Output/basic-project.test.tmp/build
RUN: at line 2: sed 's|$test_dir|/Users/buildbot/buildbot-root/aarch64-darwin/llvm-project/clang-tools-extra/test/clang-doc|g' /Users/buildbot/buildbot-root/aarch64-darwin/llvm-project/clang-tools-extra/test/clang-doc/Inputs/basic-project/database_template.json > /Users/buildbot/buildbot-root/aarch64-darwin/build/tools/clang/tools/extra/test/clang-doc/Output/basic-project.test.tmp/build/compile_commands.json
+ sed 's|$test_dir|/Users/buildbot/buildbot-root/aarch64-darwin/llvm-project/clang-tools-extra/test/clang-doc|g' /Users/buildbot/buildbot-root/aarch64-darwin/llvm-project/clang-tools-extra/test/clang-doc/Inputs/basic-project/database_template.json
RUN: at line 3: clang-doc --format=html --output=/Users/buildbot/buildbot-root/aarch64-darwin/build/tools/clang/tools/extra/test/clang-doc/Output/basic-project.test.tmp/docs --executor=all-TUs /Users/buildbot/buildbot-root/aarch64-darwin/build/tools/clang/tools/extra/test/clang-doc/Output/basic-project.test.tmp/build/compile_commands.json
+ clang-doc --format=html --output=/Users/buildbot/buildbot-root/aarch64-darwin/build/tools/clang/tools/extra/test/clang-doc/Output/basic-project.test.tmp/docs --executor=all-TUs /Users/buildbot/buildbot-root/aarch64-darwin/build/tools/clang/tools/extra/test/clang-doc/Output/basic-project.test.tmp/build/compile_commands.json
[2/3] Processing file /Users/buildbot/buildbot-root/aarch64-darwin/llvm-project/clang-tools-extra/test/clang-doc/Inputs/basic-project/src/Circle.cpp
[1/3] Processing file /Users/buildbot/buildbot-root/aarch64-darwin/llvm-project/clang-tools-extra/test/clang-doc/Inputs/basic-project/src/Rectangle.cpp
[3/3] Processing file /Users/buildbot/buildbot-root/aarch64-darwin/llvm-project/clang-tools-extra/test/clang-doc/Inputs/basic-project/src/Calculator.cpp
RUN: at line 4: FileCheck /Users/buildbot/buildbot-root/aarch64-darwin/llvm-project/clang-tools-extra/test/clang-doc/basic-project.test -input-file=/Users/buildbot/buildbot-root/aarch64-darwin/build/tools/clang/tools/extra/test/clang-doc/Output/basic-project.test.tmp/docs/index_json.js -check-prefix=JSON-INDEX
+ FileCheck /Users/buildbot/buildbot-root/aarch64-darwin/llvm-project/clang-tools-extra/test/clang-doc/basic-project.test -input-file=/Users/buildbot/buildbot-root/aarch64-darwin/build/tools/clang/tools/extra/test/clang-doc/Output/basic-project.test.tmp/docs/index_json.js -check-prefix=JSON-INDEX
RUN: at line 5: FileCheck /Users/buildbot/buildbot-root/aarch64-darwin/llvm-project/clang-tools-extra/test/clang-doc/basic-project.test -input-file=/Users/buildbot/buildbot-root/aarch64-darwin/build/tools/clang/tools/extra/test/clang-doc/Output/basic-project.test.tmp/docs/GlobalNamespace/Shape.html -check-prefix=HTML-SHAPE
+ FileCheck /Users/buildbot/buildbot-root/aarch64-darwin/llvm-project/clang-tools-extra/test/clang-doc/basic-project.test -input-file=/Users/buildbot/buildbot-root/aarch64-darwin/build/tools/clang/tools/extra/test/clang-doc/Output/basic-project.test.tmp/docs/GlobalNamespace/Shape.html -check-prefix=HTML-SHAPE
�[1m/Users/buildbot/buildbot-root/aarch64-darwin/llvm-project/clang-tools-extra/test/clang-doc/basic-project.test:64:16: �[0m�[0;1;31merror: �[0m�[1mHTML-SHAPE: expected string not found in input
�[0m// HTML-SHAPE: <h3 id="{{([0-9A-F]{40})}}">area</h3>
�[0;1;32m               ^
�[0m�[1m/Users/buildbot/buildbot-root/aarch64-darwin/build/tools/clang/tools/extra/test/clang-doc/Output/basic-project.test.tmp/docs/GlobalNamespace/Shape.html:32:53: �[0m�[0;1;30mnote: �[0m�[1mscanning from here
�[0m <p>Defined at line 13 of file ./include/Shape.h</p>
�[0;1;32m                                                    ^
�[0m�[1m/Users/buildbot/buildbot-root/aarch64-darwin/build/tools/clang/tools/extra/test/clang-doc/Output/basic-project.test.tmp/docs/GlobalNamespace/Shape.html:47:41: �[0m�[0;1;30mnote: �[0m�[1mpossible intended match here
�[0m <a href="#12896F9255F880ECD4A6482CCFA58B238FA2CC49">area</a>
�[0;1;32m                                        ^
�[0m
Input file: /Users/buildbot/buildbot-root/aarch64-darwin/build/tools/clang/tools/extra/test/clang-doc/Output/basic-project.test.tmp/docs/GlobalNamespace/Shape.html
Check file: /Users/buildbot/buildbot-root/aarch64-darwin/llvm-project/clang-tools-extra/test/clang-doc/basic-project.test

-dump-input=help explains the following input dump.

Input was:
<<<<<<
�[1m�[0m�[0;1;30m            1: �[0m�[1m�[0;1;46m<!DOCTYPE html> �[0m
�[0;1;30m            2: �[0m�[1m�[0;1;46m<meta charset="utf-8"/> �[0m
�[0;1;30m            3: �[0m�[1m�[0;1;46m<title>class Shape</title> �[0m
�[0;1;30m            4: �[0m�[1m�[0;1;46m<link rel="stylesheet" href="../clang-doc-default-stylesheet.css"/> �[0m
...