Port default-ctor nctor IL to TrackedInstructionEncoder

After rebasing onto main (which merged #11260 adding maxstack tracking),
the new 0-arg nctor codegen path in EmitUcoMethod was using the
pre-#11260 bare OpCode + Token style. Switch to the tracked encoder
helpers (LoadToken, CastClass, Call(parameterCount,…), Callvirt(parameterCount,…))
so the emitted method's maxstack is computed correctly, matching every
other IL site in TypeMapAssemblyEmitter.

Also update Generate_InheritedCtor_* / Generate_InheritedJavaInteropCtor_*
generator tests to reflect the new nctor contract: the default-ctor
branch references the target type's parameterless .ctor(),
SetPeerReference and MarkActivationPeerReplaceable — and no longer
references the legacy (IntPtr, JniHandleOwnership) /
(JniObjectReference&, JniObjectReferenceOptions) activation ctor on the
inherited base.

Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>

Author: simonrozsival

src/Microsoft.Android.Sdk.TrimmableTypeMap/Generator/TypeMapAssemblyEmitter.cs

@@ -1067,29 +1067,26 @@ MethodDefinitionHandle EmitUcoConstructor (UcoConstructorData uco, JavaPeerProxy
 				MethodAttributes.Public | MethodAttributes.Static | MethodAttributes.HideBySig,
 				encodeSig,
 				(encoder, cfb) => EmitUcoConstructorBodyWithMarshal (encoder, cfb, enc => {
-					enc.OpCode (ILOpCode.Ldtoken);
-					enc.Token (targetTypeRef);
-					enc.Call (_getTypeFromHandleRef);
-					enc.Call (_getUninitializedObjectRef);
-					enc.OpCode (ILOpCode.Castclass);
-					enc.Token (targetTypeRef);
+					enc.LoadToken (targetTypeRef);
+					enc.Call (_getTypeFromHandleRef, parameterCount: 1, returnsValue: true);
+					enc.Call (_getUninitializedObjectRef, parameterCount: 1, returnsValue: true);
+					enc.CastClass (targetTypeRef);
 					enc.StoreLocal (4);
 
 					enc.LoadLocalAddress (3); // jniRef
 					enc.LoadArgument (1);     // self
 					enc.LoadConstantI4 (0);   // JniObjectReferenceType.Invalid
-					enc.Call (_jniObjectReferenceCtorRef);
+					enc.Call (_jniObjectReferenceCtorRef, parameterCount: 2, isInstance: true);
 
 					enc.LoadLocal (4);
 					enc.LoadLocal (3);
-					enc.OpCode (ILOpCode.Callvirt);
-					enc.Token (_setPeerReferenceRef);
+					enc.Callvirt (_setPeerReferenceRef, parameterCount: 1);
 
 					enc.LoadLocal (4);
-					enc.Call (defaultCtorRef);
+					enc.Call (defaultCtorRef, parameterCount: 0, isInstance: true);
 
 					enc.LoadArgument (1); // self
-					enc.Call (_markActivationPeerReplaceableRef);
+					enc.Call (_markActivationPeerReplaceableRef, parameterCount: 1);
 				}),
 				blob => EncodeUcoConstructorLocals_DefaultConstructor (blob, targetTypeRef));
 			AddUnmanagedCallersOnlyAttribute (defaultCtorHandle);
@@ -1133,7 +1130,7 @@ MethodDefinitionHandle EmitUcoConstructor (UcoConstructorData uco, JavaPeerProxy
 						enc.Call (ctorRef, parameterCount: 2, isInstance: true);
 					}
 					enc.LoadArgument (1); // self
-					enc.Call (_markActivationPeerReplaceableRef);
+					enc.Call (_markActivationPeerReplaceableRef, parameterCount: 1);
 				}),
 				EncodeUcoConstructorLocals_JavaInterop);
 		} else {
@@ -1164,7 +1161,7 @@ MethodDefinitionHandle EmitUcoConstructor (UcoConstructorData uco, JavaPeerProxy
 						enc.Call (ctorRef, parameterCount: 2, isInstance: true);
 					}
 					enc.LoadArgument (1); // self
-					enc.Call (_markActivationPeerReplaceableRef);
+					enc.Call (_markActivationPeerReplaceableRef, parameterCount: 1);
 				}),
 				EncodeUcoConstructorLocals_Standard);
 		}

tests/Microsoft.Android.Sdk.TrimmableTypeMap.Tests/Generator/TypeMapAssemblyGeneratorTests.cs

@@ -288,7 +288,7 @@ public void Generate_LeafCtor_DoesNotUseCreateManagedPeer ()
 	}
 
 	[Fact]
-	public void Generate_InheritedCtor_ReferencesGuardAndActivationCtor ()
+	public void Generate_InheritedCtor_NctorUcoCallsDefaultConstructor ()
 	{
 		var peers = ScanFixtures ();
 		var simpleActivity = peers.First (p => p.JavaName == "my/app/SimpleActivity");
@@ -302,18 +302,24 @@ public void Generate_InheritedCtor_ReferencesGuardAndActivationCtor ()
 
 		Assert.Contains ("ShouldSkipActivation", memberNames);
 		Assert.Contains ("GetUninitializedObject", memberNames);
+		Assert.Contains ("SetPeerReference", memberNames);
+		Assert.Contains ("MarkActivationPeerReplaceable", memberNames);
 		Assert.DoesNotContain ("Invoke", memberNames);
 		Assert.DoesNotContain ("ActivateInstance", memberNames);
 		Assert.DoesNotContain ("ActivatePeerFromJavaConstructor", memberNames);
 
-		Assert.NotEmpty (FindCtorMemberRefs (reader, "Android.App", "Activity",
+		// The new no-arg nctor codegen calls the target type's parameterless .ctor()
+		// directly, not the legacy (IntPtr, JniHandleOwnership) activation ctor on the base.
+		Assert.NotEmpty (FindCtorMemberRefs (reader, "MyApp", "SimpleActivity"));
+		Assert.Empty (FindCtorMemberRefs (reader, "Android.App", "Activity",
 			"System.IntPtr", "Android.Runtime.JniHandleOwnership"));
+
 		var nctorMethodHandle = FindNctorUcoMethod (reader);
 		Assert.False (nctorMethodHandle.IsNil, "SimpleActivity should have a nctor_*_uco method");
 	}
 
 	[Fact]
-	public void Generate_InheritedJavaInteropCtor_ReferencesActivationCtor ()
+	public void Generate_InheritedJavaInteropCtor_NctorUcoCallsDefaultConstructor ()
 	{
 		var peer = MakeAcwPeer ("test/JiInheritedTarget", "Test.JiInheritedTarget", "TestAsm") with {
 			ActivationCtor = new ActivationCtorInfo {
@@ -332,10 +338,17 @@ public void Generate_InheritedJavaInteropCtor_ReferencesActivationCtor ()
 
 		var memberNames = GetMemberRefNames (reader);
 		Assert.Contains ("GetUninitializedObject", memberNames);
+		Assert.Contains ("SetPeerReference", memberNames);
+		Assert.Contains ("MarkActivationPeerReplaceable", memberNames);
 		Assert.DoesNotContain ("Invoke", memberNames);
 
-		Assert.NotEmpty (FindCtorMemberRefs (reader, "Test", "JiInheritedBase",
+		// The new no-arg nctor codegen calls the target type's parameterless .ctor()
+		// directly, not the JI-style (JniObjectReference&, JniObjectReferenceOptions)
+		// activation ctor on the inherited base.
+		Assert.NotEmpty (FindCtorMemberRefs (reader, "Test", "JiInheritedTarget"));
+		Assert.Empty (FindCtorMemberRefs (reader, "Test", "JiInheritedBase",
 			"Java.Interop.JniObjectReference&", "Java.Interop.JniObjectReferenceOptions"));
+
 		var nctorMethodHandle = FindNctorUcoMethod (reader);
 		Assert.False (nctorMethodHandle.IsNil, "The ACW peer should have a nctor_*_uco method");
 	}