LDC 1.40.0-beta4

[kinke]

Glad to announce the 4th beta for LDC 1.40. Major changes (since 
v1.39):

* Based on D ~2.110.0 (today's upstream stable).
* LLVM for prebuilt packages bumped to v18.1.8 (incl. macOS 
arm64).
* Android: NDK for prebuilt package bumped from r26d to r27.
* Emscripten: The compiler now mimicks a musl Linux platform wrt. 
extra predefined versions. ABI compatibility with clang improved 
too.
* Mainly for **distro package maintainers**: Use system zlib 
instead of Phobos' vendored version through CMake 
`-DPHOBOS_SYSTEM_ZLIB=ON`. Thanks Andrei!
* Edge-case fixes regarding IR struct layouts and link-time 
culling (for ELF targets).

Full release log and downloads:
https://github.com/ldc-developers/ldc/releases/tag/v1.40.0-beta4

Please help test, and thanks to all contributors & sponsors!