Move partial unmap handler to the native signal handler (#3437)

* Initial commit with a lot of testing stuff.

* Partial Unmap Cleanup Part 1

* Fix some minor issues, hopefully windows tests.

* Disable partial unmap tests on macos for now

Weird issue.

* Goodbye magic number

* Add COMPlus_EnableAlternateStackCheck for tests

`COMPlus_EnableAlternateStackCheck` is needed for NullReferenceException handling to work on linux after registering the signal handler, due to how dotnet registers its own signal handler.

* Address some feedback

* Force retry when memory is mapped in memory tracking

This case existed before, but returning `false` no longer retries, so it would crash immediately after unprotecting the memory... Now, we return `true` to deliberately retry.

This case existed before (was just broken by this change) and I don't really want to look into fixing the issue right now. Technically, this means that on guest code partial unmaps will retry _due to this_ rather than hitting the handler. I don't expect this to cause any issues.

This should fix random crashes in Xenoblade Chronicles 2.

* Use IsRangeMapped

* Suppress MockMemoryManager.UnmapEvent warning

This event is not signalled by the mock memory manager.

* Remove 4kb mapping

2 files changed, 15 insertions, 3 deletions

diff --git a/Ryujinx.Memory.Tests/MockVirtualMemoryManager.cs b/Ryujinx.Memory.Tests/MockVirtualMemoryManager.cs
index cad0c2b5..29922f89 100644
--- a/Ryujinx.Memory.Tests/MockVirtualMemoryManager.cs
+++ b/Ryujinx.Memory.Tests/MockVirtualMemoryManager.cs
@@ -4,7 +4,7 @@ using System.Collections.Generic;
 
 namespace Ryujinx.Memory.Tests
 {
-    class MockVirtualMemoryManager : IVirtualMemoryManager
+    public class MockVirtualMemoryManager : IVirtualMemoryManager
     {
         public bool NoMappings = false;
 
diff --git a/Ryujinx.Memory.Tests/Tests.cs b/Ryujinx.Memory.Tests/Tests.cs
index aa20c38a..45d00e51 100644
--- a/Ryujinx.Memory.Tests/Tests.cs
+++ b/Ryujinx.Memory.Tests/Tests.cs
@@ -38,9 +38,15 @@ namespace Ryujinx.Memory.Tests
             Assert.AreEqual(Marshal.ReadInt32(_memoryBlock.Pointer, 0x2040), 0xbadc0de);
         }
 
-        [Test, Explicit]
+        [Test]
         public void Test_Alias()
         {
+            if (OperatingSystem.IsMacOS())
+            {
+                // Memory aliasing tests fail on CI at the moment.
+                return;
+            }
+
             using MemoryBlock backing = new MemoryBlock(0x10000, MemoryAllocationFlags.Mirrorable);
             using MemoryBlock toAlias = new MemoryBlock(0x10000, MemoryAllocationFlags.Reserve | MemoryAllocationFlags.ViewCompatible);
 
@@ -51,9 +57,15 @@ namespace Ryujinx.Memory.Tests
             Assert.AreEqual(Marshal.ReadInt32(backing.Pointer, 0x1000), 0xbadc0de);
         }
 
-        [Test, Explicit]
+        [Test]
         public void Test_AliasRandom()
         {
+            if (OperatingSystem.IsMacOS())
+            {
+                // Memory aliasing tests fail on CI at the moment.
+                return;
+            }
+
             using MemoryBlock backing = new MemoryBlock(0x80000, MemoryAllocationFlags.Mirrorable);
             using MemoryBlock toAlias = new MemoryBlock(0x80000, MemoryAllocationFlags.Reserve | MemoryAllocationFlags.ViewCompatible);