Shorten nonzero isqrt internal comment

Author: ChaiTRex

library/core/src/num/nonzero.rs

@@ -1547,24 +1547,16 @@ macro_rules! nonzero_integer_signedness_dependent_methods {
         pub const fn isqrt(self) -> Self {
             let result = self.get().isqrt();
 
-            // SAFETY: Inform the optimizer what the range of outputs is.
-            // If testing `core` crashes with no panic message and a
-            // `num::int_sqrt::u*` test failed, it's because your edits
-            // caused these assertions or the assertions in `fn isqrt` of
-            // `uint_macros.rs` to become false.
+            // Inform the optimizer what the range of outputs is. The upper
+            // bound was already handled by the `$Uint::isqrt` call just above.
             //
-            // Integer square root is a monotonically nondecreasing
-            // function, which means that increasing the input will never
-            // cause the output to decrease.
-            //
-            // The minimum input is 1. When n is 1, sqrt(n) is 1. If n
-            // increases above 1, sqrt(n) can't decrease below 1, so sqrt(n)
-            // can't decrease below 1 no matter what n is.
-            //
-            // The maximum possible output already has an assertion in
-            // `fn isqrt` of `uint_macros.rs`.
+            // SAFETY: Integer square root is a monotonically nondecreasing
+            // function, which means that increasing the input will never cause
+            // the output to decrease. Thus, since the input for nonzero
+            // unsigned integers has a lower bound of 1, the lower bound of the
+            // result will be sqrt(1), which is 1.
             unsafe {
-                hint::assert_unchecked(result > 0);
+                hint::assert_unchecked(result >= 1);
             }
 
             // SAFETY: As explained above, the minimum integer square root is