Put Crossgen2 in sync with #54235 (#54438)

Author: trylek

src/coreclr/tools/Common/TypeSystem/Common/MetadataFieldLayoutAlgorithm.cs

@@ -782,10 +782,9 @@ public LayoutInt CalculateFieldBaseOffset(MetadataType type, bool requiresAlign8
             if (!type.IsValueType && type.HasBaseType)
             {
                 cumulativeInstanceFieldPos = type.BaseType.InstanceByteCountUnaligned;
-                if (!type.BaseType.InstanceByteCountUnaligned.IsIndeterminate)
+                if (!cumulativeInstanceFieldPos.IsIndeterminate)
                 {
-                    cumulativeInstanceFieldPos = type.BaseType.InstanceByteCountUnaligned;
-                    if (type.BaseType.IsZeroSizedReferenceType && ((MetadataType)type.BaseType).HasLayout())
+                    if (requiresAlignedBase && type.BaseType.IsZeroSizedReferenceType && ((MetadataType)type.BaseType).HasLayout())
                     {
                         cumulativeInstanceFieldPos += LayoutInt.One;
                     }

src/coreclr/tools/Common/TypeSystem/Interop/IL/MarshalUtils.cs

@@ -23,8 +23,8 @@ public static bool IsBlittableType(TypeDesc type)
                 && !baseType.IsWellKnownType(WellKnownType.Object)
                 && !baseType.IsWellKnownType(WellKnownType.ValueType);
 
-            // Type is blittable only if parent is also blittable and is not empty.
-            if (hasNonTrivialParent && (!IsBlittableType(baseType) || baseType.IsZeroSizedReferenceType))
+            // Type is blittable only if parent is also blittable.
+            if (hasNonTrivialParent && !IsBlittableType(baseType))
             {
                 return false;
             }

src/coreclr/tools/aot/ILCompiler.TypeSystem.ReadyToRun.Tests/MarshalUtilsTests.cs

@@ -74,10 +74,10 @@ public void IsBlittableType_TypeWithBlittableBase_ReturnsTrue(string className)
         [InlineData("ClassWithExplicitEmptyBase")]
         [InlineData("ClassWithExplicitEmptySizeZeroBase")]
         [InlineData("ClassWithSequentialEmptyBase")]
-        public void IsBlittableType_TypeWithEmptyBase_ReturnsFalse(string className)
+        public void IsBlittableType_TypeWithEmptyBase_ReturnsTrue(string className)
         {
             TypeDesc classWithEmptyBase = _testModule.GetType("Marshalling", className);
-            Assert.False(MarshalUtils.IsBlittableType(classWithEmptyBase));
+            Assert.True(MarshalUtils.IsBlittableType(classWithEmptyBase));
         }
     }
 }

src/tests/issues.targets

@@ -123,9 +123,6 @@
         <ExcludeList Include="$(XunitTestBinBase)/tracing/eventpipe/eventsvalidation/ThreadPool/*">
             <Issue>https://github.com/dotnet/runtime/issues/48727</Issue>
         </ExcludeList>
-        <ExcludeList Include="$(XunitTestBinBase)/Interop/LayoutClass/LayoutClassTest/*">
-            <Issue>https://github.com/dotnet/runtime/issues/54316</Issue>
-        </ExcludeList>
     </ItemGroup>
 
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