Generate nuw GEPs for struct member accesses, as inbounds + non-negative
implies nuw.

Regression tests are updated using update scripts where possible, and by
find + replace where not.

This makes codegen for array initialization simpler in two ways:
1. Drop the zero-index GEP at the start, which is no longer needed with
opaque pointers.
2. Emit GEPs directly to the correct element, instead of having a long
chain of +1 GEPs. This is more canonical, and also avoids regressions in
unoptimized builds from #93823.

To minimize diffs in an upcoming change.

Just re-running the script to make future updates easier

The default version of OpenMP is updated from 5.0 to 5.1 which means if -fopenmp is specified but -fopenmp-version is not specified with clang, the default version of OpenMP is taken to be 5.1.  After modifying the Frontend for that, various LIT tests were updated. This patch contains all such changes. At a high level, these are the patterns of changes observed in LIT tests -

  # RUN lines which mentioned `-fopenmp-version=50` need to kept only if the IR for version 5.0 and 5.1 are different. Otherwise only one RUN line with no version info(i.e. default version) needs to be there.

  # Test cases of this sort already had the RUN lines with respect to the older default version 5.0 and the version 5.1. Only swapping the version specification flag `-fopenmp-version` from newer version RUN line to older version RUN line is required.

  # Diagnostics: Remove the 5.0 version specific RUN lines if there was no difference in the Diagnostics messages with respect to the default 5.1.

  # Diagnostics: In case there was any difference in diagnostics messages between 5.0 and 5.1, mention version specific messages in tests.

  # If the test contained version specific ifdef's e.g. "#ifdef OMP5" but there were no RUN lines for any other version than 5.X, then bring the code guarded by ifdef's outside and remove the ifdef's.

  # Some tests had RUN lines for both 5.0 and 5.1 versions, but it is found that the IR for 5.0 is not different from the 5.1, therefore such RUN lines are redundant. So, such duplicated lines are removed.

  # To generate CHECK lines automatically, use the script llvm/utils/update_cc_test_checks.py

Reviewed By: saiislam, ABataev

Differential Revision: https://reviews.llvm.org/D129635

(cherry picked from commit 9dd2999907dc791136a75238a6000f69bf67cf4e)

This patch prefixes omp outlined helpers and reduction funcs
with the original function's name.

Reviewed By: jdoerfert

Differential Revision: https://reviews.llvm.org/D140722

This reverts commit 029bfc311d4d7d3cd90be81bb08c046848796d02.

This patch attempts to prefix omp outlined helpers and reduction funcs
with the original function's name.

Reviewed By: jdoerfert

Differential Revision: https://reviews.llvm.org/D140722

This looked like a plausibly correct out of tree patch.
The changed testcases with the pragmas stripped out only use
inbounds GEPs so I assume this is correct.

The script changes over time and unrelated changes to the test check
lines should not pollute future revisions.