Fix valgrind-found uninitialized values

src/arm/arm.c

@@ -106,6 +106,7 @@ void ARMReset(struct ARMCore* cpu) {
 	cpu->executionMode = MODE_THUMB;
 	_ARMSetMode(cpu, MODE_ARM);
 
+	cpu->currentPC = 0;
 	int currentCycles = 0;
 	ARM_WRITE_PC;
 

src/gba/gba-savedata.c

@@ -46,7 +46,9 @@ void GBASavedataDeinit(struct GBASavedata* savedata) {
 	default:
 		break;
 	}
-	close(savedata->fd);
+	if (savedata->fd >= 0) {
+		close(savedata->fd);
+	}
 	savedata->type = SAVEDATA_NONE;
 }
 

src/gba/gba.c

@@ -58,6 +58,7 @@ void GBAInit(struct GBA* gba) {
 
 	GBAIOInit(gba);
 
+	gba->timersEnabled = 0;
 	memset(gba->timers, 0, sizeof(gba->timers));
 
 	gba->springIRQ = 0;

src/platform/sdl/gl-main.c

@@ -57,6 +57,7 @@ int main(int argc, char** argv) {
 	}
 
 	sigset_t signals;
+	sigemptyset(&signals);
 	sigaddset(&signals, SIGINT);
 	sigaddset(&signals, SIGTRAP);
 	pthread_sigmask(SIG_BLOCK, &signals, 0);