Improve bool.TryFormat perf (dotnet/coreclr#18711)

* Improve bool.TryFormat perf

Improves throughput by ~50%, by avoiding AsSpan().CopyTo and just writing out the characters one-by-one.  I experimented with playing the same tricks around storing the data in a ulong and blitting it out to the destination reinterpreted as a span of ulongs, but it didn't make a measurable improvement and increased the code complexity.

* Update Boolean.cs

Signed-off-by: dotnet-bot <dotnet-bot@microsoft.com>

Author: stephentoub

src/Common/src/CoreLib/System/Boolean.cs

@@ -97,18 +97,34 @@ public string ToString(IFormatProvider provider)
 
         public bool TryFormat(Span<char> destination, out int charsWritten)
         {
-            string s = m_value ? TrueLiteral : FalseLiteral;
-
-            if (s.AsSpan().TryCopyTo(destination))
+            if (m_value)
             {
-                charsWritten = s.Length;
-                return true;
+                if ((uint)destination.Length > 3) // uint cast, per https://github.com/dotnet/coreclr/issues/18688
+                {
+                    destination[0] = 'T';
+                    destination[1] = 'r';
+                    destination[2] = 'u';
+                    destination[3] = 'e';
+                    charsWritten = 4;
+                    return true;
+                }
             }
             else
             {
-                charsWritten = 0;
-                return false;
+                if ((uint)destination.Length > 4)
+                {
+                    destination[0] = 'F';
+                    destination[1] = 'a';
+                    destination[2] = 'l';
+                    destination[3] = 's';
+                    destination[4] = 'e';
+                    charsWritten = 5;
+                    return true;
+                }
             }
+
+            charsWritten = 0;
+            return false;
         }
 
         // Determines whether two Boolean objects are equal.