Add missing includes for web single thread

drivers/unix/file_access_unix.cpp

@@ -43,10 +43,7 @@
 #include <unistd.h>
 
 #include <cerrno>
-
-#if defined(TOOLS_ENABLED)
 #include <cstdlib>
-#endif
 
 void FileAccessUnix::check_errors(bool p_write) const {
 	ERR_FAIL_NULL_MSG(f, "File must be opened before use.");

modules/theora/editor/movie_writer_ogv.cpp

@@ -35,6 +35,8 @@
 #include "core/config/project_settings.h"
 #include "core/io/file_access.h"
 
+#include <cstdlib>
+
 void MovieWriterOGV::push_audio(const int32_t *p_audio_data) {
 	// Read and process more audio.
 	float **vorbis_buffer = vorbis_analysis_buffer(&vd, audio_frames);