This is a cli tool to that tests the conformance of LLVM's mustache
implementation against the public Mustache spec, hosted at
https://github.com/mustache/spec. This is a revised version of the
patches in #111487.

Co-authored-by: Peter Chou <peter.chou@mail.utoronto.ca>

This is a follow-up for
https://github.com/llvm/llvm-project/pull/101461.

This is a patch for
https://discourse.llvm.org/t/rfc-enhanced-machine-outliner-part-2-thinlto-nolto/78753.

This change follows from https://reviews.llvm.org/D156416 We include
`llvm-remark-size-diff` as a part of `llvm-remarkutil` under a
subcommand `size-diff`.

Differential Revision: https://reviews.llvm.org/D156515

[Docs] Added llvm-reduce docs in CommandGuide

Differential Revision: https://reviews.llvm.org/D146020

Fix #61313

Reviewed By: lattner

Differential Revision: https://reviews.llvm.org/D145844

Differential Revision: https://reviews.llvm.org/D136138

Originally committed in fe7a3cedf77125a6309150d85cecbc20b1a31775

Reverted in 26dd64ba9cfabe5474bb207f3b7099965f81fed7

Buildbot failures:
https://lab.llvm.org/buildbot#builders/139/builds/29663
- unittest trigger an invalid assertion.

https://lab.llvm.org/buildbot#builders/196/builds/19665
- 'has virtual functions but non-virtual destructor' warning as error.

Recommitted with fix:
- Removed the assertion.
- Added virtual destructor.

This reverts commit fe7a3cedf77125a6309150d85cecbc20b1a31775.

llvm-debuginfo-analyzer is a command line tool that processes debug
info contained in a binary file and produces a debug information
format agnostic “Logical View”, which is a high-level semantic
representation of the debug info, independent of the low-level
format.

The code has been divided into the following patches:

1) Interval tree
2) Driver and documentation
3) Logical elements
4) Locations and ranges
5) Select elements
6) Warning and internal options
7) Compare elements
8) ELF Reader
9) CodeView Reader

Full details:
https://discourse.llvm.org/t/llvm-dev-rfc-llvm-dva-debug-information-visual-analyzer/62570

This patch:

Driver and documentation
- Command line options.
- Full documentation.
- String Pool table.

Reviewed By: psamolysov, probinson

Differential Revision: https://reviews.llvm.org/D125777

This adds llvm-remarkutil. This is intended to be a general tool for doing stuff
with/to remark files.

This patch gives it the following powers:

* `bitstream2yaml` - To convert bitstream remarks to YAML
* `yaml2bitstream` - To convert YAML remarks to bitstream remarks

These are both implemented as subcommands, like

`llvm-remarkutil bitstream2yaml <input_file> -o -`

I ran into an issue where I had some bitstream remarks coming from CI, and I
wanted to be able to do stuff with them (e.g. visualize them). But then I
noticed we didn't have any tooling for doing that, so I decided to write this
thing.

Being able to output YAML as a start seemed like a good idea, since it
would allow people to reuse any tooling they may have written based around YAML
remarks.

Hopefully it can grow into a more featureful remark utility. :)

Currently there are is an outstanding performance issue (see the TODO) with
the bitstream2yaml case. I decided that I'd keep the tool small to start with
and have the yaml2bitstream and bitstream2yaml cases be symmetric.

Also I moved the remarks documentation to its own header because it seems
a little out of place with "basic commands" and "developer tools"; it's
really kind of its own thing.

Differential Revision: https://reviews.llvm.org/D133646