Add comments for Arch Linux

Author: banach-space

tools/CMakeLists.txt

@@ -11,6 +11,9 @@ target_include_directories(
   "${CMAKE_CURRENT_SOURCE_DIR}/../include")
 
 if(UNIX AND EXISTS "/etc/arch-release")
+  # LLVM is built as shared library on Arch Linux (*), so we need to link the
+  # static executable against libLLVM.so. See #117
+  # (*)  https://gitlab.archlinux.org/archlinux/packaging/packages/llvm/-/blob/main/PKGBUILD?ref_type=heads#L89
   message("LLVM is installed as shared library on Arch Linux")
   target_link_libraries(static LLVM)
 else()