LDC 1.34.0

[kinke]

Glad to announce LDC 1.34.0. Major changes:

* Based on D 2.104.2.
* Support for LLVM 16, incl. v16.0.6 for the prebuilt packages. 
Support for v9 and v10 was dropped.
* 64-bit RISC-V: Enable ISA extensions ('rv64gc') by default when 
targeting an operating system.

Full release log and downloads: 
https://github.com/ldc-developers/ldc/releases/tag/v1.34.0

Thanks to all contributors & sponsors!