Fix #19002 Error CS0503 shows the correct modifier target (#19025)

* Error CS0503 shows the correct modifier target

src/Compilers/CSharp/Portable/CSharpResources.Designer.cs

@@ -179,7 +179,7 @@ internal class CSharpResources {
         }
         
         /// <summary>
-        ///   Looks up a localized string similar to The abstract method &apos;{0}&apos; cannot be marked virtual.
+        ///   Looks up a localized string similar to The abstract {0} &apos;{1}&apos; cannot be marked virtual.
         /// </summary>
         internal static string ERR_AbstractNotVirtual {
             get {

src/Compilers/CSharp/Portable/CSharpResources.resx

@@ -1422,7 +1422,7 @@ If such a class is used as a base class and if the deriving class defines a dest
     <value>'{0}' cannot be both abstract and sealed</value>
   </data>
   <data name="ERR_AbstractNotVirtual" xml:space="preserve">
-    <value>The abstract method '{0}' cannot be marked virtual</value>
+    <value>The abstract {0} '{1}' cannot be marked virtual</value>
   </data>
   <data name="ERR_StaticConstant" xml:space="preserve">
     <value>The constant '{0}' cannot be marked static</value>

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

@@ -485,7 +485,7 @@ protected void CheckModifiersAndType(DiagnosticBag diagnostics)
             }
             else if (IsAbstract && IsVirtual)
             {
-                diagnostics.Add(ErrorCode.ERR_AbstractNotVirtual, location, this);
+                diagnostics.Add(ErrorCode.ERR_AbstractNotVirtual, location, this.Kind.Localize(), this);
             }
             else if (ContainingType.IsSealed && this.DeclaredAccessibility.HasProtected() && !this.IsOverride)
             {

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

@@ -940,7 +940,7 @@ private void CheckModifiers(Location location, DiagnosticBag diagnostics)
             }
             else if (IsAbstract && IsVirtual)
             {
-                diagnostics.Add(ErrorCode.ERR_AbstractNotVirtual, location, this);
+                diagnostics.Add(ErrorCode.ERR_AbstractNotVirtual, location, this.Kind.Localize(), this);
             }
             else if (IsAbstract && ContainingType.TypeKind == TypeKind.Struct)
             {

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

@@ -848,7 +848,7 @@ private void CheckModifiers(Location location, bool isIndexer, DiagnosticBag dia
             }
             else if (IsAbstract && IsVirtual)
             {
-                diagnostics.Add(ErrorCode.ERR_AbstractNotVirtual, location, this);
+                diagnostics.Add(ErrorCode.ERR_AbstractNotVirtual, location, this.Kind.Localize(), this);
             }
             else if (ContainingType.IsSealed && this.DeclaredAccessibility.HasProtected() && !this.IsOverride)
             {

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

@@ -7746,7 +7746,7 @@ abstract public class cly : clx
         [Fact]
         public void CS0503ERR_AbstractNotVirtual01()
         {
-            var text = @"namespace NS
+            var source = @"namespace NS
 {
     abstract public class clx
     {
@@ -7757,14 +7757,24 @@ abstract public class clx
     } // class clx
 }
 ";
-            var comp = DiagnosticsUtils.VerifyErrorsAndGetCompilationWithMscorlib(text,
-                new ErrorDescription { Code = (int)ErrorCode.ERR_AbstractNotVirtual, Line = 5, Column = 40 },
-                new ErrorDescription { Code = (int)ErrorCode.ERR_AbstractNotVirtual, Line = 6, Column = 41 },
-                new ErrorDescription { Code = (int)ErrorCode.ERR_AbstractNotVirtual, Line = 7, Column = 40 },
-                new ErrorDescription { Code = (int)ErrorCode.ERR_AbstractNotVirtual, Line = 8, Column = 53 });
 
-            var ns = comp.SourceModule.GlobalNamespace.GetMembers("NS").Single() as NamespaceSymbol;
-            // TODO...
+            var comp = CreateStandardCompilation(source).VerifyDiagnostics(
+                // (7,40): error CS0503: The abstract property 'clx.P' cannot be marked virtual
+                //         virtual abstract public object P { get; set; }
+                Diagnostic(ErrorCode.ERR_AbstractNotVirtual, "P").WithArguments("property", "NS.clx.P").WithLocation(7, 40),
+                // (6,41): error CS0503: The abstract method 'clx.M2<T>(T)' cannot be marked virtual
+                //         abstract virtual protected void M2<T>(T t);
+                Diagnostic(ErrorCode.ERR_AbstractNotVirtual, "M2").WithArguments("method", "NS.clx.M2<T>(T)").WithLocation(6, 41),
+                // (5,40): error CS0503: The abstract method 'clx.M1()' cannot be marked virtual
+                //         abstract virtual internal void M1();
+                Diagnostic(ErrorCode.ERR_AbstractNotVirtual, "M1").WithArguments("method", "NS.clx.M1()").WithLocation(5, 40),
+                // (8,53): error CS0503: The abstract event 'clx.E' cannot be marked virtual
+                //         virtual abstract public event System.Action E;
+                Diagnostic(ErrorCode.ERR_AbstractNotVirtual, "E").WithArguments("event", "NS.clx.E").WithLocation(8, 53));
+
+            var nsNamespace = comp.SourceModule.GlobalNamespace.GetMembers("NS").Single() as NamespaceSymbol;
+            var clxClass = nsNamespace.GetMembers("clx").Single() as NamedTypeSymbol;
+            Assert.Equal(9, clxClass.GetMembers().Length);
         }
 
         [Fact]