Fix: [Emscripten] compile with exceptions enabled, as our AIs depend …

…on it

Also parts of the saveload code does, and some other places. This
does slow down builds, but for most computers this will not be
measurable. At least, the ones I had access to I could not find
a difference in FPS, mainly as that is heavily limited by the Hz
of the screens of the computer.

Either way, it is better to have a full functional game than a
fast one in my opinion

CMakeLists.txt

@@ -242,6 +242,8 @@ if(EMSCRIPTEN)
     # Allow heap-growth, and start with a bigger memory size.
     target_link_libraries(WASM::WASM INTERFACE "-s ALLOW_MEMORY_GROWTH=1")
     target_link_libraries(WASM::WASM INTERFACE "-s INITIAL_MEMORY=33554432")
+    target_link_libraries(WASM::WASM INTERFACE "-s DISABLE_EXCEPTION_CATCHING=0")
+    add_definitions(-s DISABLE_EXCEPTION_CATCHING=0)
 
     # Export functions to Javascript.
     target_link_libraries(WASM::WASM INTERFACE "-s EXPORTED_FUNCTIONS='[\"_main\", \"_em_openttd_add_server\"]' -s EXTRA_EXPORTED_RUNTIME_METHODS='[\"cwrap\"]'")