Apply noreturn attribute where applicable (#1532)

src/code/code_800D31A0.c

@@ -3,7 +3,7 @@
 
 u32 gIsCtrlr2Valid = false;
 
-void func_800D31A0(void) {
+NORETURN void func_800D31A0(void) {
     osSyncPrintf(VT_FGCOL(RED) "\n**** Freeze!! ****\n" VT_RST);
     while (true) {
         Sleep_Msec(1000);

src/code/fault.c

@@ -1304,19 +1304,25 @@ void Fault_HungupFaultClient(const char* exp1, const char* exp2) {
  * error occurs. The parameters specify two messages detailing the error, one
  * or both may be NULL.
  */
-void Fault_AddHungupAndCrashImpl(const char* exp1, const char* exp2) {
+NORETURN void Fault_AddHungupAndCrashImpl(const char* exp1, const char* exp2) {
     FaultClient client;
     s32 pad;
 
     Fault_AddClient(&client, Fault_HungupFaultClient, (void*)exp1, (void*)exp2);
     *(u32*)0x11111111 = 0; // trigger an exception via unaligned memory access
+
+    // Since the above line triggers an exception and transfers execution to the fault handler
+    // this function does not return and the rest of the function is unreachable.
+#ifdef __GNUC__
+    __builtin_unreachable();
+#endif
 }
 
 /**
  * Like `Fault_AddHungupAndCrashImpl`, however provides a fixed message containing
  * filename and line number
  */
-void Fault_AddHungupAndCrash(const char* file, s32 line) {
+NORETURN void Fault_AddHungupAndCrash(const char* file, s32 line) {
     char msg[256];
 
     sprintf(msg, "HungUp %s:%d", file, line);