pumped up the LruCache benchmark invocation count to get more accurate numbers

[Aaronontheweb]

BenchmarkDotNet=v0.13.1, OS=Windows 10.0.19041.1165 (2004/May2020Update/20H1)
AMD Ryzen 7 1700, 1 CPU, 16 logical and 8 physical cores
.NET SDK=5.0.302
  [Host]     : .NET Core 3.1.17 (CoreCLR 4.700.21.31506, CoreFX 4.700.21.31502), X64 RyuJIT
  Job-ZKSOFC : .NET Core 3.1.17 (CoreCLR 4.700.21.31506, CoreFX 4.700.21.31502), X64 RyuJIT

InvocationCount=10000000  

Method	Mean	Error	StdDev	Gen 0	Gen 1	Allocated
ActorRefResolveMissBenchmark	315.21 ns	1.730 ns	1.445 ns	0.0325	0.0001	136 B
ActorRefResolveHitBenchmark	58.23 ns	0.332 ns	0.294 ns	-	-	-
AddressHitBenchmark	70.96 ns	0.120 ns	0.106 ns	-	-	-
ActorPathCacheHitBenchmark	58.41 ns	0.054 ns	0.048 ns	-	-	-
ActorPathCacheMissBenchmark	74.21 ns	1.106 ns	0.924 ns	-	-	-

Doesn't look nearly as bad as #5248 had me believe....

[Aaronontheweb]

.NET 5 numbers look similar:

BenchmarkDotNet=v0.13.1, OS=Windows 10.0.19041.1165 (2004/May2020Update/20H1)
AMD Ryzen 7 1700, 1 CPU, 16 logical and 8 physical cores
.NET SDK=5.0.302
  [Host]     : .NET 5.0.8 (5.0.821.31504), X64 RyuJIT
  Job-GKICJT : .NET 5.0.8 (5.0.821.31504), X64 RyuJIT

InvocationCount=10000000  

Method	Mean	Error	StdDev	Gen 0	Gen 1	Allocated
ActorRefResolveMissBenchmark	274.75 ns	0.472 ns	0.419 ns	0.0325	0.0001	136 B
ActorRefResolveHitBenchmark	58.67 ns	0.076 ns	0.072 ns	-	-	-
AddressHitBenchmark	64.69 ns	0.141 ns	0.125 ns	-	-	-
ActorPathCacheHitBenchmark	58.32 ns	0.104 ns	0.098 ns	-	-	-
ActorPathCacheMissBenchmark	51.68 ns	0.709 ns	0.592 ns	-	-	-