deps,v8: silence V8 self-deprecation warnings

[refack]

With current config we get C++ deprecation warning while building V8 from it's own code for use of methods that the V8 team deprecated. IMO this is not directly informative for node's build process, so this PR silences these warnings, unless explicitly configured to show them.

CI: https://ci.nodejs.org/job/node-test-pull-request/19994/

/CC @nodejs/v8 @nodejs/build-files

Checklist

• make -j4 test (UNIX), or vcbuild test (Windows) passes
• commit message follows commit guidelines

[nodejs-github-bot]

@refack build started: https://ci.nodejs.org/blue/organizations/jenkins/node-test-pull-request-lite-pipeline/detail/node-test-pull-request-lite-pipeline/2179/pipeline

[ryzokuken]

Harsh but fair. It's not really up to contributors to core to fix those anyway.

[mhdawson]

@refack just to clarify, these are warnings only for V8 code itself, not Node.js using V8 deprecated functions right?

[addaleax]

@refack As I understand it, this would disable deprecation warnings for addons as well, unless they explicitly enable it? How are addon authors going to know that their code will be broken?

[refack]

just to clarify, these are warnings only for V8 code itself, not Node.js using V8 deprecated functions right?

As I understand it, this would disable deprecation warnings for addons as well, unless they explicitly enable it?

These settings are just for the the compilation of the V8 code itself (I should not have turned them on in the first place when we migrated them from the GN setup).

For all other code (the files in /src/ and addons) to get v8.h to emit those warnings we explicitly define these flags in

node/common.gypi

Lines 300 to 305 in fe7ce8c

	# Defines these mostly for node-gyp to pickup, and warn addon authors of
	# imminent V8 deprecations, also to sync how dependencies are configured.
	'defines': [
	'V8_DEPRECATION_WARNINGS',
	'V8_IMMINENT_DEPRECATION_WARNINGS',
	],

Resume CI: https://ci.nodejs.org/job/node-test-pull-request/20077/ ✅

[addaleax]

Landed in d1b7193

[addaleax]

I’m labelling this dont-land-on-v11.x because it doesn’t apply cleanly and, since it’s developer-targeting, shouldn’t cause trouble to not have it in v11.x. Feel free to backport it if that makes sense to you, though.