Corrects Clint module, and adds rust clint debugger

bench/programs_rust/fpga-lib/src/vga.rs

@@ -119,6 +119,47 @@ impl VGA
         });
     }
 
+    fn digit_count(mut val: u64) -> u64
+    {
+        let mut i = 0;
+        while val != 0
+        {
+            val /= 10;
+            i += 1;
+        }
+
+        i
+    }
+
+    pub unsafe fn draw_u64(x: u16, y: u16, mut val: u64, color: Color, bg_color: Color)
+    {
+        if val == 0
+        {
+            unsafe { Self::draw_char_bg(x, y, '0', color, bg_color) }
+            return;
+        }
+        let digit_count = Self::digit_count(val) - 1;
+        let mut i = digit_count as u16;
+        while val != 0
+        {
+            let digit = val % 10;
+            val /= 10;
+
+            let char = (digit as u8) + b'0';
+            unsafe {
+                Self::draw_char_bg(
+                    x + i * (FONT_WIDTH as u16),
+                    y,
+                    char as char,
+                    color,
+                    bg_color,
+                )
+            };
+
+            i -= 1;
+        }
+    }
+
     unsafe fn font_plate_index(x: u16, y: u16) -> bool
     {
         let pixel_index = (y as usize) * FONTPLATE_WIDTH + (x as usize);