LLVM 18.1.5

[xhochy]

Blockers for merging this PR and thus enabling the compilers in conda-forge (indentation denotes dependency; c.f. list from #123):

• llvmdev 18.1.5 llvmdev-feedstock#263
  • clangdev 18.1.5 clangdev-feedstock#284
    • Build for LLVM 18 cctools-and-ld64-feedstock#65 (only needs major version)
    • compiler-rt v18.1.5 compiler-rt-feedstock#106
      • openmp v18.1.5 openmp-feedstock#123
    • libcxx 17.0.6 libcxx-feedstock#131 (waiting for MacOS 10.13 roll-out)
  • lld v18.1.5 lld-feedstock#91

Related feedstocks for LLVM 18.1.4 support more generally:

• clang 18.1.5 clang-win-activation-feedstock#36 (windows side of this PR; needs this PR)
• Add clang 18 ctng-compiler-activation-feedstock#104 (only needs major version)
• flang v18.1.5 flang-feedstock#49 (needs mlir, openmp, compiler-rt)
• Add testing against clang 17 & 18 libcxx-testing-feedstock#6 (only needs major version)
• lldb v18.1.5 lldb-feedstock#66 (needs this PR)
• mlir 18.1.5 mlir-feedstock#69 (needs llvmdev)
• mlir-python-bindings v18.1.5 mlir-python-bindings-feedstock#26 (needs llvmdev & mlir)

[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) and found it was in an excellent condition.

[xhochy]

@conda-forge/clang-compiler-activation Ready for a merge.