Implemented a bunch of FILE stdio functions

.gitmodules

@@ -0,0 +1,3 @@
+[submodule "photon/libc/sys/magenta/libmagenta"]
+	path = photon/libc/sys/magenta/libmagenta
+	url = https://gitlab.com/doorstuck/magenta/libmagenta.git

photon/libc/stdio/fdopen.c

@@ -0,0 +1,15 @@
+#include <stdio.h>
+#include <stdlib.h>
+#include <__fio.h>
+
+FILE *fdopen(int fd, const char *mode)
+{
+    struct __io_file *fp = malloc(sizeof(*fp));
+    int res = __fio_fdopen(fd, mode, fp);
+    if (res != 0) {
+        free(fp);
+        return NULL;
+    }
+
+    return fp;
+}

photon/libc/stdio/fflush.c

@@ -0,0 +1,13 @@
+#include <stdio.h>
+#include <stdlib.h>
+#include <__fio.h>
+
+int fflush(FILE *fp)
+{
+    int res = __fio_flush(fp);
+    if (res != 0) {
+        return -1;
+    }
+
+    return 0;
+}

photon/libc/stdio/fopen.c

@@ -0,0 +1,15 @@
+#include <stdio.h>
+#include <stdlib.h>
+#include <__fio.h>
+
+FILE *fopen(const char *path, const char *mode)
+{
+    struct __io_file *fp = malloc(sizeof(*fp));
+    int res = __fio_fopen(path, mode, fp);
+    if (res != 0) {
+        free(fp);
+        return NULL;
+    }
+
+    return fp;
+}

photon/libc/stdio/freopen.c

@@ -0,0 +1,16 @@
+#include <stdio.h>
+#include <stdlib.h>
+#include <__fio.h>
+
+FILE *freopen(const char *path, const char *mode, FILE *fp)
+{
+    int res = __fio_fclose(fp);
+
+    res = __fio_fopen(path, mode, fp);
+    if (res != 0) {
+        free(fp);
+        return NULL;
+    }
+
+    return fp;
+}

photon/libc/stdio/puts.c

@@ -2,5 +2,10 @@
 
 int puts(const char *str)
 {
-    return fputs(str, stdout);
+    int ret = fputs(str, stdout);
+    if (ret < 0) {
+        return ret;
+    }
+
+    return fputc('\n', stdout);
 }