Initial PollardRho implementation for GPU. Added pool for accelerator streams shared across the threads. GPU processing performance and stabilization improvements. GpuUInt128.BinaryGcd switched to the version which outperformed other in benchmarks.

PerfectNumbers.Core/Gpu/MersenneNumberLucasLehmerGpuTester.cs

@@ -147,13 +147,11 @@ public class MersenneNumberLucasLehmerGpuTester
             return false;
         }
 
-        GpuPrimeWorkLimiter.Acquire();
         bool result;
         if (exponent >= 128UL)
         {
             if (!TryGetNttParameters(exponent, out var nttMod, out var primitiveRoot))
             {
-				GpuPrimeWorkLimiter.Release();
                 throw new NotSupportedException("NTT parameters for the given exponent are not available.");
             }
 
@@ -161,6 +159,7 @@ public class MersenneNumberLucasLehmerGpuTester
         }
         else
         {
+        	GpuPrimeWorkLimiter.Acquire();
             var accelerator = AcceleratorPool.Shared.Rent();
             var stream = accelerator.CreateStream();
             var modulus = new GpuUInt128(((UInt128)1 << (int)exponent) - 1UL); // TODO: Cache these Mersenne moduli per exponent so LL GPU runs skip rebuilding them every launch.