LLVM 19.1.0.rc3

[h-vetinari]

Blockers for merging this PR and thus enabling the compilers in conda-forge (indentation denotes dependency):

• llvmdev v19.1.0.rc3 llvmdev-feedstock#284
  • clangdev 19.1.0.rc3 clangdev-feedstock#308
    • Build for LLVM 19 rc cctools-and-ld64-feedstock#73 (only needs major version)
    • compiler-rt v19.1.0.rc3 compiler-rt-feedstock#118
      • openmp v19.1.0.rc3 openmp-feedstock#142
    • libcxx v19.1.0.rc3 libcxx-feedstock#182
  • lld 19.1.0.rc3 lld-feedstock#103

Related feedstocks for LLVM 19.1.0 support more generally:

• https://github.com/conda-forge/clang-win-activation-feedstock (needs this PR)
• https://github.com/conda-forge/ctng-compiler-activation-feedstock (only needs major version)
• flang v19.1.0.rc3 flang-feedstock#70 (needs mlir, compiler-rt)
• https://github.com/conda-forge/libcxx-testing-feedstock (only needs major version)
• https://github.com/conda-forge/lldb-feedstock (needs this PR)
• mlir v19.1.0.rc3 mlir-feedstock#79 (needs llvmdev)
• Version 19.1.0.rc3 mlir-python-bindings-feedstock#35 (needs llvmdev & mlir)
• https://github.com/conda-forge/r_clang_activation-feedstock (needs clangdev)

[conda-forge-webservices]

Hi! This is the friendly automated conda-forge-linting service.

I just wanted to let you know that I linted all conda-recipes in your PR (recipe/meta.yaml) and found it was in an excellent condition.