Misc.

src/Compilers/CSharp/Portable/SymbolDisplay/SymbolDisplayVisitor.Types.cs

@@ -592,7 +592,7 @@ private static string GetSpecialTypeName(INamedTypeSymbol symbol)
                     return null;
             }
 
-            static bool isNativeInt(INamedTypeSymbol symbol) => symbol is NamedTypeSymbol { IsNativeInt: true };
+            static bool isNativeInt(INamedTypeSymbol symbol) => symbol.GetSymbol<NamedTypeSymbol>()?.IsNativeInt == true;
         }
 
         private void AddTypeKind(INamedTypeSymbol symbol)

src/Compilers/CSharp/Test/Semantic/Semantics/NativeIntTests.cs

@@ -82,9 +82,9 @@ static void verify(CSharpCompilation comp)
                 var type0 = method.Parameters[0].Type;
                 var type1 = method.Parameters[1].Type;
                 Assert.Equal(SpecialType.None, type0.SpecialType);
-                Assert.False(((NamedTypeSymbol)type0).IsNativeInt);
+                Assert.False(IsNativeInt(type0));
                 Assert.Equal(SpecialType.System_UIntPtr, type1.SpecialType);
-                Assert.True(((NamedTypeSymbol)type1).IsNativeInt);
+                Assert.True(IsNativeInt(type1));
             }
         }
 
@@ -119,12 +119,17 @@ static void verify(CSharpCompilation comp)
                 var type0 = method.Parameters[0].Type;
                 var type1 = method.Parameters[1].Type;
                 Assert.Equal(SpecialType.System_Int16, type0.SpecialType);
-                Assert.False(((NamedTypeSymbol)type0).IsNativeInt);
+                Assert.False(IsNativeInt(type0));
                 Assert.Equal(SpecialType.System_UIntPtr, type1.SpecialType);
-                Assert.True(((NamedTypeSymbol)type1).IsNativeInt);
+                Assert.True(IsNativeInt(type1));
             }
         }
 
+        private static bool IsNativeInt(ITypeSymbol type)
+        {
+            return type.GetSymbol<NamedTypeSymbol>()?.IsNativeInt == true;
+        }
+
         // PROTOTYPE: nint and nuint should be allowed.
         [Fact]
         public void MemberName()

src/Compilers/CSharp/Test/Symbol/SymbolDisplay/SymbolDisplayTests.cs

@@ -7832,7 +7832,7 @@ class B
 
             var method = comp.GetMember<MethodSymbol>("B.F1");
             Verify(
-                SymbolDisplay.ToDisplayParts(method, formatWithoutSpecialTypes),
+                method.ToDisplayParts(formatWithoutSpecialTypes),
                 "static void F1(IntPtr x, UIntPtr y)",
                 SymbolDisplayPartKind.Keyword,
                 SymbolDisplayPartKind.Space,
@@ -7850,7 +7850,7 @@ class B
                 SymbolDisplayPartKind.ParameterName,
                 SymbolDisplayPartKind.Punctuation);
             Verify(
-                SymbolDisplay.ToDisplayParts(method, formatWithSpecialTypes),
+                method.ToDisplayParts(formatWithSpecialTypes),
                 "static void F1(nint x, nuint y)",
                 SymbolDisplayPartKind.Keyword,
                 SymbolDisplayPartKind.Space,
@@ -7870,26 +7870,26 @@ class B
 
             method = comp.GetMember<MethodSymbol>("B.F2");
             Verify(
-                SymbolDisplay.ToDisplayParts(method, formatWithoutSpecialTypes),
+                method.ToDisplayParts(formatWithoutSpecialTypes),
                 "static void F2(IntPtr x, IntPtr y)");
             Verify(
-                SymbolDisplay.ToDisplayParts(method, formatWithSpecialTypes),
+                method.ToDisplayParts(formatWithSpecialTypes),
                 "static void F2(nint x, IntPtr y)");
 
             method = comp.GetMember<MethodSymbol>("B.F3");
             Verify(
-                SymbolDisplay.ToDisplayParts(method, formatWithoutSpecialTypes),
+                method.ToDisplayParts(formatWithoutSpecialTypes),
                 "static void F3(IntPtr? x, UIntPtr? y)");
             Verify(
-                SymbolDisplay.ToDisplayParts(method, formatWithSpecialTypes),
+                method.ToDisplayParts(formatWithSpecialTypes),
                 "static void F3(nint? x, UIntPtr? y)");
 
             method = comp.GetMember<MethodSymbol>("B.F4");
             Verify(
-                SymbolDisplay.ToDisplayParts(method, formatWithoutSpecialTypes),
+                method.ToDisplayParts(formatWithoutSpecialTypes),
                 "static void F4(IntPtr[] x, A<UIntPtr> y)");
             Verify(
-                SymbolDisplay.ToDisplayParts(method, formatWithSpecialTypes),
+                method.ToDisplayParts(formatWithSpecialTypes),
                 "static void F4(nint[] x, A<nuint> y)");
         }
     }