Fix tests

src/Compilers/CSharp/Portable/Symbols/Source/SourceOrdinaryMethodSymbol.cs

@@ -608,6 +608,10 @@ private static void PartialMethodChecks(SourceOrdinaryMethodSymbol definition, S
                 checkNullableMethodOverride = false;
                 diagnostics.Add(ErrorCode.ERR_PartialMethodReturnTypeDifference, implementation.Locations[0]);
             }
+            else if (definition.RefKind != implementation.RefKind)
+            {
+                diagnostics.Add(ErrorCode.ERR_PartialMethodRefReturnDifference, implementation.Locations[0]);
+            }
             else if (MemberSignatureComparer.ConsideringTupleNamesCreatesDifference(definition, implementation))
             {
                 diagnostics.Add(ErrorCode.ERR_PartialMethodInconsistentTupleNames, implementation.Locations[0], definition, implementation);
@@ -619,10 +623,6 @@ private static void PartialMethodChecks(SourceOrdinaryMethodSymbol definition, S
                 static FormattedSymbol getFormattedSymbol(Symbol symbol) => new FormattedSymbol(symbol, SymbolDisplayFormat.MinimallyQualifiedFormat);
             }
 
-            if (definition.RefKind != implementation.RefKind)
-            {
-                diagnostics.Add(ErrorCode.ERR_PartialMethodRefReturnDifference, implementation.Locations[0]);
-            }
 
             if (definition.IsStatic != implementation.IsStatic)
             {

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

@@ -3305,6 +3305,7 @@ class C2 : IA, IB
         }
 
         [Fact]
+        [WorkItem(45519, "https://github.com/dotnet/roslyn/issues/45519")]
         public void Partial_01()
         {
             var source =
@@ -3316,7 +3317,13 @@ public void Partial_01()
     static partial void F2(nuint x);
 }";
             var comp = CreateCompilation(source, parseOptions: TestOptions.Regular9);
-            comp.VerifyDiagnostics();
+            comp.VerifyDiagnostics(
+                // (4,25): error CS8824: Partial method declarations 'void Program.F2(nuint x)' and 'void Program.F2(UIntPtr x)' must have identical parameter types and identical return types.
+                //     static partial void F2(System.UIntPtr x) { }
+                Diagnostic(ErrorCode.ERR_PartialMethodSignatureDifference, "F2").WithArguments("void Program.F2(nuint x)", "void Program.F2(UIntPtr x)").WithLocation(4, 25),
+                // (5,25): error CS8824: Partial method declarations 'void Program.F1(IntPtr x)' and 'void Program.F1(nint x)' must have identical parameter types and identical return types.
+                //     static partial void F1(nint x) { }
+                Diagnostic(ErrorCode.ERR_PartialMethodSignatureDifference, "F1").WithArguments("void Program.F1(IntPtr x)", "void Program.F1(nint x)").WithLocation(5, 25));
         }
 
         [Fact]

src/Compilers/CSharp/Test/Symbol/Symbols/ExtendedPartialMethodsTests.cs

@@ -2957,9 +2957,9 @@ partial class C
 }";
             var comp = CreateCompilation(source, parseOptions: TestOptions.RegularWithExtendedPartialMethods);
             comp.VerifyDiagnostics(
-                // (4,35): error CS8142: Both partial method declarations, 'C.M1()' and 'C.M1()', must use the same tuple element names.
-                //     public partial (int x, int y) M1();
-                Diagnostic(ErrorCode.ERR_PartialMethodInconsistentTupleNames, "M1").WithArguments("C.M1()", "C.M1()").WithLocation(4, 35));
+                // (5,37): error CS8142: Both partial method declarations, 'C.M1()' and 'C.M1()', must use the same tuple element names.
+                //     public partial (int x1, int y1) M1() => default; // 1
+                Diagnostic(ErrorCode.ERR_PartialMethodInconsistentTupleNames, "M1").WithArguments("C.M1()", "C.M1()").WithLocation(5, 37));
         }
 
         [Fact, WorkItem(44930, "https://github.com/dotnet/roslyn/issues/44930")]