clang-tidy: run modernize-deprecated-headers

core/hw/sh4/dyna/shil_canonical.h

@@ -97,7 +97,7 @@ extern "C" f32 fipr_asm(float* fn, float* fm);
 
 #if SHIL_MODE==1 || SHIL_MODE==2
 //only in structs we use the code :)
-#include <math.h>
+#include <cmath>
 #include "types.h"
 #include "shil.h"
 #include "decoder.h"

core/hw/sh4/modules/serial.cpp

@@ -2,9 +2,9 @@
 	Dreamcast serial port.
 	This is missing most of the functionality, but works for KOS (And thats all that uses it)
 */
-#include <stdlib.h>
+#include <cerrno>
+#include <cstdlib>
 #include <fcntl.h>
-#include <errno.h>
 #ifndef _WIN32
 #include <unistd.h>
 #include <sys/ioctl.h>

core/imgread/ioctl.cpp

@@ -3,7 +3,7 @@
 #ifdef _WIN32
 #include "common.h"
 
-#include <stddef.h>
+#include <cstddef>
 #include <windows.h>
 
 #include <ntddscsi.h>