[xcode11.4] [tests] Add `.cctor` execution to introspection (#7987)

This will spot cases like https://github.com/xamarin/xamarin-macios/issues/7959
where a type (static) constructor can fail at runtime, leading to
`TypeLoadException`

Ideally it's covered by it's own tests but it's better covered twice
than never :)

On iOS 64bits [1] simulator we hit some failures [2], later, if the
`.cctor` is executed. It's not a big deal to avoid those types since
we it will be executed on devices later.

[1] API not present on 32bits

[2] Fixing the following triggers similar failures for `DCDevice`

```
ApiClassPtrTest.VerifyClassPtr: class_ptr and RegisterAttribute are different: NFCIso15693CustomCommandConfiguration
Expected: 0
But was: 140735471513712

ApiSelectorTest.StaticMethods: 7 errors found in 2788 static selector validated:
CoreNFC.NFCIso15693ReaderSession : readingAvailable
CoreNFC.NFCNdefMessage : ndefMessageWithData:
CoreNFC.NFCNdefPayload : wellKnownTypeURIPayloadWithString:
CoreNFC.NFCNdefPayload : wellKnownTypeURIPayloadWithURL:
CoreNFC.NFCNdefPayload : wellKnownTypeTextPayloadWithString:locale:
CoreNFC.NFCNdefReaderSession : readingAvailable
CoreNFC.NFCReaderSession : readingAvailable
Expected: 0
But was: 7
```

Co-authored-by: Sebastien Pouliot <sebastien.pouliot@gmail.com>

tests/introspection/ApiTypeTest.cs

@@ -0,0 +1,58 @@
+using System;
+using System.Reflection;
+using System.Runtime.CompilerServices;
+
+using NUnit.Framework;
+using Xamarin.Utils;
+
+using Foundation;
+using ObjCRuntime;
+
+namespace Introspection {
+
+	[TestFixture]
+	// we want the tests to be available because we use the linker
+	[Preserve (AllMembers = true)]
+	public class ApiTypeTest : ApiBaseTest {
+
+		bool Skip (Type type)
+		{
+			switch (type.Namespace) {
+#if __IOS__
+			// running the .cctor on the simulator works... but makes some other CoreNFC intro tests fail later
+			// we'll still get the results from device tests
+			case "CoreNFC":
+			case "DeviceCheck":
+				// we can't call the `NFCNdefReaderSession.ReadingAvailable` API on 32bits (PlatformNotSupportedException)
+				// and if we call it then the .cctor is executed and we get the same failures :()
+				return ((IntPtr.Size == 4) || (Runtime.Arch == Arch.SIMULATOR));
+#endif
+			default:
+				return false;
+			}
+		}
+
+		[Test]
+		public void StaticCtor ()
+		{
+			ContinueOnFailure = true;
+			foreach (Type t in Assembly.GetTypes ()) {
+				if (Skip (t))
+					continue;
+
+				var cctor = t.GetConstructor (BindingFlags.Static | BindingFlags.NonPublic, null, Type.EmptyTypes, null);
+				if (cctor == null)
+					continue;
+				// we don't skip based on availability attributes since the execution of .cctor can easily happen indirectly and
+				// we rather catch them all here *now* than trying to figure out how to replicate the specific conditions *later*
+				try {
+					RuntimeHelpers.RunClassConstructor (t.TypeHandle);
+				}
+				catch (TypeInitializationException e) {
+					ReportError ($"{t.FullName} .cctor could not execute properly: {e}");
+				}
+			}
+			AssertIfErrors ($"{Errors} execution failure(s)");
+		}
+	}
+}

tests/introspection/Mac/introspection-mac.csproj

@@ -132,6 +132,9 @@
     <Compile Include="..\ApiFrameworkTest.cs">
       <Link>ApiFrameworkTest.cs</Link>
     </Compile>
+    <Compile Include="..\ApiTypeTest.cs">
+      <Link>ApiTypeTest.cs</Link>
+    </Compile>
   </ItemGroup>
   <ItemGroup>
     <ProjectReference Include="..\..\..\external\guiunit\src\framework\GuiUnit_NET_4_5.csproj">

tests/introspection/iOS/introspection-ios.csproj

@@ -223,6 +223,9 @@
     <Compile Include="..\ApiFrameworkTest.cs">
       <Link>ApiFrameworkTest.cs</Link>
     </Compile>
+    <Compile Include="..\ApiTypeTest.cs">
+      <Link>ApiTypeTest.cs</Link>
+    </Compile>
   </ItemGroup>
   <ItemGroup>
     <None Include="Info.plist">