LibTest: Add more numeric generators

Rename unsigned_int generator to number_u32.
Add generators:
- number_u64
- number_f64
- percentage

AK/Random.cpp

@@ -5,6 +5,8 @@
  */
 
 #include <AK/Random.h>
+#include <AK/UFixedBigInt.h>
+#include <AK/UFixedBigIntDivision.h>
 
 namespace AK {
 
@@ -28,4 +30,16 @@ u32 get_random_uniform(u32 max_bounds)
     return random_value % max_bounds;
 }
 
+u64 get_random_uniform_64(u64 max_bounds)
+{
+    // Uses the same algorithm as `get_random_uniform`,
+    // by replacing u64 with u128 and u32 with u64.
+    const u64 max_usable = UINT64_MAX - static_cast<u64>((static_cast<u128>(UINT64_MAX) + 1) % max_bounds);
+    auto random_value = get_random<u64>();
+    for (int i = 0; i < 20 && random_value > max_usable; ++i) {
+        random_value = get_random<u64>();
+    }
+    return random_value % max_bounds;
+}
+
 }