Add hello world test ROM

test_roms/HelloWorldSVC/source/main.c

@@ -0,0 +1,20 @@
+#include <3ds.h>
+#include <stdint.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+
+int main(int argc, char** argv) {
+    // Put the string on the heap to make sure heap initialization works
+    const char* buffer = calloc(6969, sizeof(char));
+    strcpy(buffer, "Hello world\n");
+
+    svcOutputDebugString(buffer, strlen(buffer));
+
+    // I hate C's UB rules around infinite loops
+    while (true) {
+        __asm__ volatile ("" ::: "memory");
+    }
+
+	return 0;
+}