TurboShaft is a new, CFG-based IR for TurboFan.
This CL adds the basic IR and bidirectional translation from/to
TurboFan's sea-of-nodes-based IR for some common operators (still
incomplete even for JS).

Bug: v8:12783
Change-Id: I162fdf10d583a9275a9f655f5b44b888faf813f6
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/3563562Reviewed-by: Clemens Backes <clemensb@chromium.org>
Reviewed-by: Maya Lekova <mslekova@chromium.org>
Reviewed-by: Nico Hartmann <nicohartmann@chromium.org>
Commit-Queue: Tobias Tebbi <tebbi@chromium.org>
Cr-Commit-Position: refs/heads/main@{#80136}

Changes:
- Remove subtyping checks from value-type.h and move them to dedicated
  files. Leave a limited version in value-type.h for testing.
- Implement subtyping for struct and array types, according to the
  wasm-gc proposal.
- Implement type equivalence checking.
- Introduce a subtyping relation cache in WasmModule.
- Rename IsSubTypeOf -> IsSubtypeOf.
- Fix v8 possible bug where iterator_range took two unused type
  parameters.
- Add unittests for subtyping.

Bug: v8:7748
Change-Id: I0ddbda4145e0412196dcf4fc63f3c5875fb3ab5a
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/2228497
Commit-Queue: Manos Koukoutos <manoskouk@chromium.org>
Reviewed-by: Clemens Backes <clemensb@chromium.org>
Reviewed-by: Jakob Kummerow <jkummerow@chromium.org>
Cr-Commit-Position: refs/heads/master@{#68192}

The current implementation takes forwarding reference arguments, which
is fine when you call it with rvalues, like
make_iterator_range(V.begin(), V.end()). If you call it with lvalues
though, it doesn't do what you'd expect. ForwardIterator becomes a
reference:

Foo I = V.begin();
make_iterator_range(I, I); //ForwardIterator is deduced as Foo&

Since iterator are supposed to be small, no harm in passing them by
value.

Change-Id: I151c87304949d810c72c42f60e9d1a7151f61f83
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/2020780
Commit-Queue: Philip Pfaffe <pfaffe@chromium.org>
Reviewed-by: Clemens Backes <clemensb@chromium.org>
Cr-Commit-Position: refs/heads/master@{#66007}

This removes the {base::ReversedAdapter} class and uses
{base::iterator_range} instead. The types are inferred from what
{std::rbegin} and {std::rend} return.

Since src/base/adapters.h would only contain this one method after
this refactoring, it was merged into src/base/iterator.h.
Some includes of src/base/adapters.h were unused and hence dropped.

R=mlippautz@chromium.org

Bug: v8:9396
Change-Id: I597172ec790193b73af196d1afcd64bbed0a597d
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/1798432Reviewed-by: Michael Lippautz <mlippautz@chromium.org>
Reviewed-by: Michael Starzinger <mstarzinger@chromium.org>
Commit-Queue: Clemens Hammacher <clemensh@chromium.org>
Cr-Commit-Position: refs/heads/master@{#63703}

Even though both are allowed in the style guide, it recommends to use
'using', as its syntax is more consistent with the rest of C++.
This CL turns all typedefs in base code to 'using' declarations.

R=mlippautz@chromium.org

Bug: v8:8834
Change-Id: Ic5c3d7fa2e50938c6f43e9ff304dc2289fed1133
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/1547650Reviewed-by: Michael Lippautz <mlippautz@chromium.org>
Commit-Queue: Clemens Hammacher <clemensh@chromium.org>
Cr-Commit-Position: refs/heads/master@{#60546}

Bug: v8:6494
Change-Id: Ie6f91c3bad38e467dd047f4d2848473cc4085c2a
Reviewed-on: https://chromium-review.googlesource.com/536397
Commit-Queue: Loo Rong Jie <loorongjie@gmail.com>
Reviewed-by: Jochen Eisinger <jochen@chromium.org>
Reviewed-by: Clemens Hammacher <clemensh@chromium.org>
Cr-Commit-Position: refs/heads/master@{#46004}

This introduces iterators for the parameters and return types of a
signature. This required extending the constructor of iterator_range
for perfect forwarding.

I also moved the HasJSCompatibleSignature to a header file in order to
reuse it from the interpreter.

R=ahaas@chromium.org, titzer@chromium.org

Change-Id: Ie77f87ef87fdfd3138b2106640ac7c481cf247e6
Reviewed-on: https://chromium-review.googlesource.com/455777
Commit-Queue: Clemens Hammacher <clemensh@chromium.org>
Reviewed-by: Andreas Haas <ahaas@chromium.org>
Reviewed-by: Ben Titzer <titzer@chromium.org>
Cr-Commit-Position: refs/heads/master@{#43854}

We have the BytecodeIterator with next() and has_next() methods, and
pc_offset() and current() accessors.
This CL adds an interface to iterate over the opcodes or offsets in a
C++ foreach loop.

R=titzer@chromium.org

Review-Url: https://codereview.chromium.org/2587143002
Cr-Commit-Position: refs/heads/master@{#41851}

TEST=unittests
R=titzer@chromium.org

Review URL: https://codereview.chromium.org/810683003

Cr-Commit-Position: refs/heads/master@{#25834}