fix #4547 - wasm -out without file extension

src/build_settings.cpp

@@ -2054,7 +2054,7 @@ gb_internal bool init_build_paths(String init_filename) {
 
 	// Do we have an extension? We might not if the output filename was supplied.
 	if (bc->build_paths[BuildPath_Output].ext.len == 0) {
-		if (build_context.metrics.os == TargetOs_windows || build_context.build_mode != BuildMode_Executable) {
+		if (build_context.metrics.os == TargetOs_windows || is_arch_wasm() || build_context.build_mode != BuildMode_Executable) {
 			bc->build_paths[BuildPath_Output].ext = copy_string(ha, output_extension);
 		}
 	}