[clang] [clang-repl] Implement LoadDynamicLibrary for clang-repl wasm use cases (PR #133037)

[Anutosh Bhat via cfe-commits]

anutosh491 wrote:

The above failure reported doesn't look related. Cherry picking commit for 20.1.3

/cherry-pick [8f56394](https://github.com/llvm/llvm-project/commit/8f56394487a4d454be0637667267ad37bd636d0f)

https://github.com/llvm/llvm-project/pull/133037