[clang-repl] Implement LoadDynamicLibrary for clang-repl wasm use cases (#133037)
**Currently we don't make use of the JIT for the wasm use cases so the
approach using the execution engine won't work in these cases.**
Rather if we use dlopen. We should be able to do the following
(demonstrating through a toy project)
1) Make use of LoadDynamicLibrary through the given implementation
```
extern "C" EMSCRIPTEN_KEEPALIVE int load_library(const char *name) {
auto Err = Interp->LoadDynamicLibrary(name);
if (Err) {
llvm::logAllUnhandledErrors(std::move(Err), llvm::errs(), "load_library error: ");
return -1;
}
return 0;
}
```
2) Add a button to call load_library once the library has been added in
our MEMFS (currently we have symengine built as a SIDE MODULE and we are
loading it)