Plume front arm support

[mcrosson]

This PR addresses #394 and #400

Changes

• Update Dockerfile to add necessary lld dependency on arm platforms via a helper script
• Run the build/install of plume-front with the necessary linker=lld option on arm platforms via a helper script
• Add rust-toolchain to Docker container along with Cargo files to ensure the right rust toolchain is selected for later steps

Builds Tested On

• x86-64
• arm64 (aarch64)
• arm32 (armv7l)

Noteworthy items

• The rust wasm packages do NOT include rustc-lld for arm
• The lld binaries published by llvm.org will NOT build plume-front with linker=lld rust args
• lld built from sources (what this patch does) on arm DOES build plume-front with linker=lld rust args

[codecov]

Codecov Report

Merging #402 into master will not change coverage.
The diff coverage is n/a.

@@           Coverage Diff           @@
##           master     #402   +/-   ##
=======================================
  Coverage   27.88%   27.88%           
=======================================
  Files          63       63           
  Lines        7252     7252           
=======================================
  Hits         2022     2022           
  Misses       5230     5230

[trinity-1686a]

I'd prefer plume-front.sh and wasm-deps.sh to be put in the script folder, else it seems all good

[trinity-1686a]

Builds Tested On

• x86-64
• arm64 (aarch64)
• arm32 (armv7l)

Are you sure you don't have uncommitted changes? Compilation failed for me with x86-64, with the issue about scoping lint being experimental

[vielmetti]

The lld binaries published by llvm.org will NOT build plume-front with linker=lld rust args

@mcrosson do you recall what's missing with the llvm distributed lld binaries? I wonder if that's something that might be fixed upstream.

[mcrosson]

@vielmetti IIRC the Rust packaging does not include arm32 or 64 as tier 1 for lld-wasm. I think it's on the WASM side? My memory is mildly hazy, there were a lot of tickets that I read and I'm still not familiar with the rust ecosystem.