Changes

[libc++] Add comment in atomic test to explain why part of it is disabled on Apple

[MemProf] Rename HeapProfiler to MemProfiler for consistency

This is consistent with the clang option added in
7ed8124d46f94601d5f1364becee9cee8538265e, and the comments on the
runtime patch in D87120.

Differential Revision: https://reviews.llvm.org/D87622

[gn build] Port 226d80ebe20

[docs][NewPM] Add docs for writing NPM passes

As to not conflict with the legacy PM example passes under
llvm/lib/Transforms/Hello, this is under HelloNew. This makes the
CMakeLists.txt and general directory structure less confusing for people
following the example.

Much of the doc structure was taken from WritinAnLLVMPass.rst.

This adds a HelloWorld pass which simply prints out each function name.

More will follow after this, e.g. passes over different units of IR, analyses.
https://llvm.org/docs/WritingAnLLVMPass.html contains a lot more.

Reviewed By: ychen, asbirlea

Differential Revision: https://reviews.llvm.org/D86979

[Asan] Fix false leak report

If user thread is in the allocator, the allocator
may have no pointer into future user's part of
the allocated block. AddrIsInside ignores such
pointers and lsan reports a false memory leak.

Reviewed By: morehouse

Differential Revision: https://reviews.llvm.org/D87552

Make namespace handling uniform across dialect backends.

Now backends spell out which namespace they want to be in, instead of relying on
clients #including them inside already-opened namespaces. This also means that
cppNamespaces should be fully qualified, and there's no implicit "::mlir::"
prepended to them anymore.

Reviewed By: mehdi_amini

Differential Revision: https://reviews.llvm.org/D86811

Update PowerPC backend ownership in CODE_OWNERS.TXT

[AMDGPU] Add XDL resource to scheduling model

Reviewed By: rampitec

Differential Revision: https://reviews.llvm.org/D87621

[SelectionDAG] Use Align/MaybeAlign in calls to getLoad/getStore/getExtLoad/getTruncStore.

The versions that take 'unsigned' will be removed in the future.

I tried to use getOriginalAlign instead of getAlign in some
places. getAlign factors in the minimum alignment implied by
the offset in the pointer info. Since we're also passing the
pointer info we can use the original alignment.

Reviewed By: arsenm

Differential Revision: https://reviews.llvm.org/D87592

[libc++] Make rotate a constexpr.

This patch makes `std::rotate` a constexpr. In doing so, this patch also
updates the internal `__move` and `__move_backward` funtions to be
constexpr.

Reviewed By: ldionne

Differential Revision: https://reviews.llvm.org/D65721

[libc++] Finish implementing P0202R3

cppreference lists the support for this paper as partial.
I found 4 functions which the paper marks as `constexpr`,
but did not use the appropriate macro.

Differential Revision: https://reviews.llvm.org/D84275

Fix MLIR standalone example to properly handle namespace

ODS TableGen backend now requires to spell out which namespace they have
to be nested in, in an absolute way.

[libc++][test] Portability fix of std::strstreambuf constructor test

The standard does not require the constructor `strstreambuf(streamsize alsize_arg = 0)`
leave the stream array unallocated when called with parameter `alsize_arg > 0`.
Conformant implementations of this constructor may allocate minimal `alsize_arg`
number of bytes forcing `str()` method to return non-null pointer.

Thanks to Andrey Maksimov for the patch.

Differential Revision: https://reviews.llvm.org/D72465

[docs] Update OrcV1 removal timeline.

[PruneEH][NFC] Use CallGraphUpdater in PruneEH

In preparation for porting the pass to NPM.

Reviewed By: asbirlea

Differential Revision: https://reviews.llvm.org/D87632