Add precompilation instructions for lazy artifacts.

[maleadt]

Avoids the load-time compilation seen with lazy artifacts, such as in LLVMExtra_jll.

Before:

julia> @time_imports using LLVMExtra_jll
[ Info: Precompiling LLVMExtra_jll [dad2f222-ce93-54a1-a47d-0025e8a3acab](cache misses: wrong source (3), incompatible header (3), mismatched flags (2))
Precompiling LLVMExtra_jll finished.
  2 dependencies successfully precompiled in 2 seconds. 28 already precompiled.
      0.9 ms  Printf
      8.5 ms  Dates
      0.8 ms  TOML
      0.6 ms  NetworkOptions
               ┌ 1.9 ms OpenSSL_jll.__init__()
      5.6 ms  OpenSSL_jll 52.83% compilation time
               ┌ 0.7 ms LibSSH2_jll.__init__()
      1.6 ms  LibSSH2_jll
               ┌ 0.9 ms LibGit2_jll.__init__()
      1.5 ms  LibGit2_jll
      4.7 ms  LibGit2
      3.9 ms  ArgTools
               ┌ 0.7 ms nghttp2_jll.__init__()
      1.4 ms  nghttp2_jll
               ┌ 1.2 ms Zlib_jll.__init__()
      1.9 ms  Zlib_jll
               ┌ 1.0 ms LibCURL_jll.__init__()
      1.7 ms  LibCURL_jll
               ┌ 0.0 ms MozillaCACerts_jll.__init__()
      0.7 ms  MozillaCACerts_jll
               ┌ 0.0 ms LibCURL.__init__()
      1.3 ms  LibCURL
               ┌ 3.2 ms Downloads.Curl.__init__()
      8.4 ms  Downloads
      1.4 ms  Tar
               ┌ 0.0 ms p7zip_jll.__init__()
      0.9 ms  p7zip_jll
      0.7 ms  UUIDs
      0.8 ms  Logging
               ┌ 0.0 ms Pkg.__init__()
     80.3 ms  Pkg
      1.0 ms  LazyArtifacts
      1.0 ms  Preferences
      1.0 ms  JLLWrappers
               ┌ 42.3 ms LLVMExtra_jll.__init__() 99.44% compilation time
    178.2 ms  LLVMExtra_jll 23.59% compilation time

After:

julia> @time_imports using LLVMExtra_jll
[ Info: Precompiling LLVMExtra_jll [dad2f222-ce93-54a1-a47d-0025e8a3acab](cache misses: wrong source (3), incompatible header (3), mismatched flags (2))
Precompiling LLVMExtra_jll finished.
  2 dependencies successfully precompiled in 2 seconds. 28 already precompiled.
      0.9 ms  Printf
      8.9 ms  Dates
      0.8 ms  TOML
      0.7 ms  NetworkOptions
               ┌ 1.9 ms OpenSSL_jll.__init__()
      5.3 ms  OpenSSL_jll 51.79% compilation time
               ┌ 0.6 ms LibSSH2_jll.__init__()
      1.3 ms  LibSSH2_jll
               ┌ 1.0 ms LibGit2_jll.__init__()
      1.6 ms  LibGit2_jll
      4.6 ms  LibGit2
      3.9 ms  ArgTools
               ┌ 0.6 ms nghttp2_jll.__init__()
      1.3 ms  nghttp2_jll
               ┌ 1.2 ms Zlib_jll.__init__()
      1.9 ms  Zlib_jll
               ┌ 1.0 ms LibCURL_jll.__init__()
      1.7 ms  LibCURL_jll
               ┌ 0.0 ms MozillaCACerts_jll.__init__()
      0.7 ms  MozillaCACerts_jll
               ┌ 0.0 ms LibCURL.__init__()
      1.2 ms  LibCURL
               ┌ 3.0 ms Downloads.Curl.__init__()
      7.9 ms  Downloads
      1.3 ms  Tar
               ┌ 0.0 ms p7zip_jll.__init__()
      0.8 ms  p7zip_jll
      0.7 ms  UUIDs
      0.7 ms  Logging
               ┌ 0.0 ms Pkg.__init__()
     81.3 ms  Pkg
      0.9 ms  LazyArtifacts
      1.0 ms  Preferences
      0.9 ms  JLLWrappers
               ┌ 0.2 ms LLVMExtra_jll.__init__()
    135.4 ms  LLVMExtra_jll

I don't particularly like the explicit nasty precompile statements, but AFAIU a precompilation workload was tried in the past and removed because it triggered actual compilation.

[topolarity]

Is this better done in a precompile workload in LazyArtifacts / Pkg itself?

None of the types look specific to JLLWrappers

[maleadt]

Yes, but then we don't get this into user's hands anytime soon.

[topolarity]

That's good motivation, just wanted to verify

We should still add it in both places so that newer Julia versions don't end up with the machine code duplicated in all of their JLL cache files needlessly. Julia should be able to recognize the CodeInstance is in a pre-existing pkgimage and avoid re-serializing it, if our precompilation policy is implemented correctly now

[maleadt]

CI fixed, and precompilation upstreamed to LazyArtifacts/Pkg.