Add support for fflush and close syscalls

arch/mips.c

@@ -74,4 +74,32 @@ int32_t openat(int32_t fd, const char* filename, uint32_t flags, uint32_t mode)
   return file;
 }
 
+int close(unsigned int fd){
+  int rtn = 0;
+  asm ( 
+    "move $a0, %1\n"
+    "li $v0, 4006\n"
+    "syscall\n"
+    "move %0, $v0\n"
+    : "=r"(rtn)
+    : "r" (fd)
+    : "a0", "v0"
+  );
+  return rtn;
+}
+
+int fsync(unsigned int fd){
+  int rtn = 0;
+  asm ( 
+    "move $a0, %1\n"
+    "li $v0, 4118\n"
+    "syscall\n"
+    "move %0, $v0\n"
+    : "=r"(rtn)
+    : "r" (fd)
+    : "a0", "v0"
+  );
+  return rtn;
+}
+
 #endif