[clang] [llvm] [Libomptarget] Statically link all plugin runtimes (PR #87009)

[Joseph Huber via cfe-commits]

jhuber6 wrote:

Going to land this soon.

@jplehr @estewart08 @ronlieb Applied this on the AMD fork, here the diff.
 https://gist.github.com/jhuber6/e856fbe9c73acea13b6d30b20605c73e

https://github.com/llvm/llvm-project/pull/87009