Update diagnostic message

src/Compilers/CSharp/Portable/CSharpResources.resx

@@ -6866,7 +6866,7 @@ To remove the warning, you can use /reference instead (set the Embed Interop Typ
     <value>Compiling requires binding the lambda expression many times. Consider declaring the lambda expression with explicit parameter types, or if the containing method call is generic, consider using explicit type arguments.</value>
   </data>
   <data name="INF_IdentifierConflictWithContextualKeyword" xml:space="preserve">
-    <value>'{0}' is a contextual keyword, with a specific meaning, in language version {1} or later. Use '@{0}' to avoid a breaking change when compiling with different language versions.</value>
+    <value>'{0}' is a contextual keyword in property accessors starting in language version {1}. Use '@{0}' instead.</value>
   </data>
   <data name="INF_IdentifierConflictWithContextualKeyword_Title" xml:space="preserve">
     <value>Identifier is a contextual keyword, with a specific meaning, in a later language version.</value>

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

@@ -4010,10 +4010,10 @@ static void N(int q)
                 // (24,17): error CS0136: A local or parameter named 'value' cannot be declared in this scope because that name is used in an enclosing local scope to define a local or parameter
                 //             int value = 0; // CS0136
                 Diagnostic(ErrorCode.ERR_LocalIllegallyOverrides, "value").WithArguments("value").WithLocation(24, 17),
-                // (24,17): info CS9258: 'value' is a contextual keyword, with a specific meaning, in language version preview or later. Use '@value' to avoid a breaking change when compiling with different language versions.
+                // (24,17): info CS9258: 'value' is a contextual keyword in property accessors starting in language version preview. Use '@value' instead.
                 //             int value = 0; // CS0136
                 Diagnostic(ErrorCode.INF_IdentifierConflictWithContextualKeyword, "value = 0").WithArguments("value", "preview").WithLocation(24, 17),
-                // (25,15): info CS9258: 'value' is a contextual keyword, with a specific meaning, in language version preview or later. Use '@value' to avoid a breaking change when compiling with different language versions.
+                // (25,15): info CS9258: 'value' is a contextual keyword in property accessors starting in language version preview. Use '@value' instead.
                 //             M(value);
                 Diagnostic(ErrorCode.INF_IdentifierConflictWithContextualKeyword, "value").WithArguments("value", "preview").WithLocation(25, 15),
                 // (30,35): error CS0136: A local or parameter named 'q' cannot be declared in this scope because that name is used in an enclosing local scope to define a local or parameter
@@ -4028,13 +4028,13 @@ static void N(int q)
                 // (9,17): error CS0136: A local or parameter named 'y' cannot be declared in this scope because that name is used in an enclosing local scope to define a local or parameter
                 //             int y = 0; // CS0136
                 Diagnostic(ErrorCode.ERR_LocalIllegallyOverrides, "y").WithArguments("y").WithLocation(9, 17),
-                // (24,17): info CS9258: 'value' is a contextual keyword, with a specific meaning, in language version preview or later. Use '@value' to avoid a breaking change when compiling with different language versions.
+                // (24,17): info CS9258: 'value' is a contextual keyword in property accessors starting in language version preview. Use '@value' instead.
                 //             int value = 0; // CS0136
                 Diagnostic(ErrorCode.INF_IdentifierConflictWithContextualKeyword, "value = 0").WithArguments("value", "preview").WithLocation(24, 17),
                 // (24,17): error CS0136: A local or parameter named 'value' cannot be declared in this scope because that name is used in an enclosing local scope to define a local or parameter
                 //             int value = 0; // CS0136
                 Diagnostic(ErrorCode.ERR_LocalIllegallyOverrides, "value").WithArguments("value").WithLocation(24, 17),
-                // (25,15): info CS9258: 'value' is a contextual keyword, with a specific meaning, in language version preview or later. Use '@value' to avoid a breaking change when compiling with different language versions.
+                // (25,15): info CS9258: 'value' is a contextual keyword in property accessors starting in language version preview. Use '@value' instead.
                 //             M(value);
                 Diagnostic(ErrorCode.INF_IdentifierConflictWithContextualKeyword, "value").WithArguments("value", "preview").WithLocation(25, 15));
         }

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

@@ -2495,7 +2495,7 @@ public byte MyProp
                     // (12,14): error CS0136: A local or parameter named 'x' cannot be declared in this scope because that name is used in an enclosing local scope to define a local or parameter
                     //         long x = 1; // 0136
                     Diagnostic(ErrorCode.ERR_LocalIllegallyOverrides, "x").WithArguments("x").WithLocation(12, 14),
-                    // (20,17): info CS9258: 'value' is a contextual keyword, with a specific meaning, in language version preview or later. Use '@value' to avoid a breaking change when compiling with different language versions.
+                    // (20,17): info CS9258: 'value' is a contextual keyword in property accessors starting in language version preview. Use '@value' instead.
                     //             int value; // 0136
                     Diagnostic(ErrorCode.INF_IdentifierConflictWithContextualKeyword, "value").WithArguments("value", "preview").WithLocation(20, 17),
                     // (20,17): error CS0136: A local or parameter named 'value' cannot be declared in this scope because that name is used in an enclosing local scope to define a local or parameter