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

[Anutosh Bhat via cfe-commits]

anutosh491 wrote:

For anyone concerned,

Such a feature would be tested out in downstream projects like [cppinterop](https://github.com/compiler-research/CppInterOp) and [xeus-cpp](https://github.com/compiler-research/xeus-cpp) as currently llvm doesn't have a concrete structure to test clang-repl in the browser.

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