[wasm-split] Remove module elements in bulk (NFC)

[aheejin]

Previously we removed module elements one by one within a loop. But because Module stores a module element in both a map and a vector, removing a single module element using removeModuleElement is O(N), because it needs to shift all vector elements after it:

binaryen/src/wasm/wasm.cpp

Lines 1970 to 1979 in 302396a

	template<typename Vector, typename Map>
	void removeModuleElement(Vector& v, Map& m, Name name) {
	m.erase(name);
	for (size_t i = 0; i < v.size(); i++) {
	if (v[i]->name == name) {
	v.erase(v.begin() + i);
	break;
	}
	}
	}

This removes module elements in bulk using removeModuleElements, which does the shifting only once.

binaryen/src/wasm/wasm.cpp

Lines 2004 to 2018 in 302396a

	template<typename Vector, typename Map, typename Elem>
	void removeModuleElements(Vector& v,
	Map& m,
	std::function<bool(Elem* elem)> pred) {
	for (auto it = m.begin(); it != m.end();) {
	if (pred(it->second)) {
	it = m.erase(it);
	} else {
	it++;
	}
	}
	v.erase(
	std::remove_if(v.begin(), v.end(), [&](auto& e) { return pred(e.get()); }),
	v.end());
	}

Combining with #8986, acx_gallery's running time improved by 50.3% (30s -> 15s), and essentials by 60.8% (230s -> 90s). (for Jul 2026 version)

I guess the main reason for the running time increase in #8441 was this O(N) removeModuleElement called within a loop after all.

[tlively]

Nice!