abseil-cpp: Add package

[vidplace7]

Maintainer: me
Compile tested:

• OpenWRT One master/snapshot (local)
• CI at openwrt-meshtastic

Description:
Adds new package abseil-cpp. This is a dependency for many Google C libraries / projects. Notably protobuf >= 22.x, but also: gRPC, tensorflow, and many others.

Pre-requisite in order to update the protobuf package.
https://protobuf.dev/support/migration/#abseil

[vidplace7]

CC @BKPepe

[vidplace7]

PowerPC is not a supported platform for abseil-cpp, causing builds/CI to fail on these platforms.

[8/245] Building CXX object absl/base/CMakeFiles/base.dir/internal/unscaledcycleclock.cc.o
FAILED: absl/base/CMakeFiles/base.dir/internal/unscaledcycleclock.cc.o 
#error Must implement UnscaledCycleClock::Frequency()

Should probably append @!powerpc to the DEPENDS

EDIT: Addressed with patches from OpenEmbedded / Void Linux

[commodo]

i just feel like randomly ranting here that C++ is a terrible language, mostly because people tend to write weirdly-complicated code (using template magic), and it eventually can need a ton of RAM just to compile things, which makes it's usage in the embedded space all the more weird (or seemingly out of place)

this PR however, is fine as-is :)

[vidplace7]

Per @vortexilation #25566 (comment) this addition breaks builds of the node package. I was able to reproduce this failure.

# make package/node/compile V=s
../deps/v8/third_party/abseil-cpp/absl/container/internal/hashtablez_sampler.cc:75:6: error: no declaration matches 'void absl::lts_20240722::container_internal::HashtablezInfo::PrepareForSampling(int64_t, size_t)'

Node implements a bundled abseil-cpp which appears to conflict with the shared abseil-cpp implemented in this package.

CC: @nxhack

[vortexilation]

@vidplace7
You need the patch from here (beginning).

About segmentation fault report in that issue, I don't encountered it anymore, please confirm.

You can confirm it with :

make package/node-yarn/host/{clean,compile} -j1 V=s 2>&1 | tee output.log

If it's ended as node-yarn installed then it doesn't segmentation anymore, before it was happened at the process of compiling node-yarn.

[vidplace7]

https://github.com/nodejs/node/blob/v22.11.0/deps/v8/DEPS#L358-L361
https://chromium.googlesource.com/external/github.com/abseil/abseil-cpp/+/c0bec1a748..d802708117

@vortexilation NodeJS should probably continue to use it's own bundled abseil-cpp, as it is a "forked" chromium variant with additional google patches applied.

Instead of patching to include the shared absl, node should entirely ignore the abseil-cpp shared package installation.

[vortexilation]

@vidplace7
Around 2 weeks ago, I have reported it upstream but still no reply.

[EDIT]
Posted new patch. Please test it.