Replace cannot usage with can not in comments

Author: trueb2

library/core/src/time.rs

@@ -1483,7 +1483,7 @@ macro_rules! try_from_secs {
         let exp = ((bits >> $mant_bits) & EXP_MASK) as i16 + MIN_EXP;
 
         let (secs, nanos) = if exp < -31 {
-            // the input represents less than 1ns and cannot be rounded to it
+            // the input represents less than 1ns and can not be rounded to it
             (0u64, 0u32)
         } else if exp < 0 {
             // the input is less than 1 second
@@ -1501,7 +1501,7 @@ macro_rules! try_from_secs {
             let add_ns = !(rem_msb || (is_even && is_tie));
 
             // f32 does not have enough precision to trigger the second branch
-            // since it cannot represent numbers between 0.999_999_940_395 and 1.0.
+            // since it can not represent numbers between 0.999_999_940_395 and 1.0.
             let nanos = nanos + add_ns as u32;
             if ($mant_bits == 23) || (nanos != NANOS_PER_SEC) { (0, nanos) } else { (1, 0) }
         } else if exp < $mant_bits {
@@ -1520,7 +1520,7 @@ macro_rules! try_from_secs {
             let add_ns = !(rem_msb || (is_even && is_tie));
 
             // f32 does not have enough precision to trigger the second branch.
-            // For example, it cannot represent numbers between 1.999_999_880...
+            // For example, it can not represent numbers between 1.999_999_880...
             // and 2.0. Bigger values result in even smaller precision of the
             // fractional part.
             let nanos = nanos + add_ns as u32;