Replace multi-loaderallocator hash implementation in MethodDescBackpatchInfo (dotnet#22285)

* GCHeapHash
- Hashtable implementation for runtime use
- Implementation written in C++
- Data storage in managed heap memory
- Based on SHash design, but using managed memory

CrossLoaderAllocatorHash
- Hash for c++ Pointer to C++ pointer where the lifetimes are controlled by different loader allocators
 - Support for add/remove/visit all entries of 1 key/visit all entries/ remove all entries of 1 key
- Supports holding data which is unmanaged, but data items themselves can be of any size (key/value are templated types)

* Swap MethodDescBackpatchInfo to use the CrossLoaderAllocatorHash

* The MethodDescBackpatchCrst needs to be around an allocation
- Adjust the Crst so that it can safely be used around code which allocates
- Required moving its use out from within the EESuspend logic used in rejit

Author: davidwrighton

src/System.Private.CoreLib/System.Private.CoreLib.csproj

@@ -232,7 +232,9 @@
     <Compile Include="$(BclSourcesRoot)\System\Reflection\RuntimePropertyInfo.cs" />
     <Compile Include="$(BclSourcesRoot)\System\Resources\ManifestBasedResourceGroveler.CoreCLR.cs" />
     <Compile Include="$(BclSourcesRoot)\System\RtType.cs" />
+    <Compile Include="$(BclSourcesRoot)\System\Runtime\CompilerServices\CrossLoaderAllocatorHashHelpers.cs" />
     <Compile Include="$(BclSourcesRoot)\System\Runtime\CompilerServices\DependentHandle.cs" />
+    <Compile Include="$(BclSourcesRoot)\System\Runtime\CompilerServices\GCHeapHash.cs" />
     <Compile Include="$(BclSourcesRoot)\System\Runtime\CompilerServices\ICastableHelpers.cs" />
     <Compile Include="$(BclSourcesRoot)\System\Runtime\CompilerServices\jithelpers.cs" />
     <Compile Include="$(BclSourcesRoot)\System\Runtime\CompilerServices\RuntimeFeature.CoreCLR.cs" />

src/System.Private.CoreLib/src/System/Runtime/CompilerServices/CrossLoaderAllocatorHashHelpers.cs

@@ -0,0 +1,37 @@
+// Licensed to the .NET Foundation under one or more agreements.
+// The .NET Foundation licenses this file to you under the MIT license.
+// See the LICENSE file in the project root for more information.
+
+using System;
+using System.Runtime.InteropServices;
+
+namespace System.Runtime.CompilerServices
+{
+    /// <summary>
+    /// Managed structure used by CrossLoaderAllocatorHeap to isolate per LoaderAllocator
+    /// data. 
+    /// </summary>
+    [StructLayout(LayoutKind.Sequential)]
+    internal class LAHashDependentHashTracker
+    {
+        GCHandle _dependentHandle;
+        IntPtr _loaderAllocator;
+
+        ~LAHashDependentHashTracker()
+        {
+            if (_dependentHandle.IsAllocated)
+                _dependentHandle.Free();
+        }
+    }
+
+    /// <summary>
+    /// Managed structure used by CrossLoaderAllocatorHeap to hold a set of references
+    /// to LAHashDependentHashTracker's
+    /// </summary>
+    [StructLayout(LayoutKind.Sequential)]
+    internal class LAHashKeyToTrackers
+    {
+        object _trackerOrTrackerSet;
+        object _laLocalKeyValueStore;
+    }
+}

src/System.Private.CoreLib/src/System/Runtime/CompilerServices/GCHeapHash.cs

@@ -0,0 +1,21 @@
+// Licensed to the .NET Foundation under one or more agreements.
+// The .NET Foundation licenses this file to you under the MIT license.
+// See the LICENSE file in the project root for more information.
+
+using System;
+using System.Runtime.InteropServices;
+
+namespace System.Runtime.CompilerServices
+{
+    /// <summary>
+    /// Managed structure used by GCHeapHash in CLR to provide a hashtable manipulated
+    /// by C++ runtime code which manages its memory in the GC heap.
+    /// </summary>
+    [StructLayout(LayoutKind.Sequential)]
+    internal class GCHeapHash
+    {
+        Array _data;
+        int _count;
+        int _deletedCount;
+    }
+}

src/inc/CrstTypes.def

@@ -491,8 +491,8 @@ End
 
 // Used to synchronize all rejit information stored in a given AppDomain.
 Crst ReJITDomainTable
-    AcquiredBefore LoaderHeap SingleUseLock DeadlockDetection JumpStubCache DebuggerController MethodDescBackpatchInfoTracker
-    AcquiredAfter ReJITGlobalRequest ThreadStore GlobalStrLiteralMap SystemDomain DebuggerMutex
+    AcquiredBefore LoaderHeap SingleUseLock DeadlockDetection JumpStubCache DebuggerController FuncPtrStubs
+    AcquiredAfter ReJITGlobalRequest ThreadStore GlobalStrLiteralMap SystemDomain DebuggerMutex MethodDescBackpatchInfoTracker
 End
 
 // Used to synchronize all global requests (which may span multiple AppDomains) which add
@@ -701,5 +701,5 @@ Crst COMCallWrapper
 End
 
 Crst MethodDescBackpatchInfoTracker
-    AcquiredBefore FuncPtrStubs
+    AcquiredBefore FuncPtrStubs ThreadStore SystemDomain
 End