Give a specific message when analyzer references a more-recent compiler version

src/Compilers/CSharp/Portable/CSharpResources.resx

@@ -6637,6 +6637,12 @@ To remove the warning, you can use /reference instead (set the Embed Interop Typ
   <data name="WRN_AnalyzerReferencesFramework_Title" xml:space="preserve">
     <value>The loaded assembly references .NET Framework, which is not supported.</value>
   </data>
+  <data name="WRN_AnalyzerReferencesNewerCompiler" xml:space="preserve">
+    <value>The assembly '{0}' references version '{1}' of the compiler, which is newer than the currently running version '{2}'.</value>
+  </data>
+  <data name="WRN_AnalyzerReferencesNewerCompiler_Title" xml:space="preserve">
+    <value>The assembly references a newer version of the compiler than the currently running version.</value>
+  </data>
   <data name="ERR_BadFieldTypeInRecord" xml:space="preserve">
     <value>The type '{0}' may not be used for a field of a record.</value>
   </data>

src/Compilers/CSharp/Portable/Errors/ErrorCode.cs

@@ -2099,6 +2099,8 @@ internal enum ErrorCode
         ERR_FixedFieldMustNotBeRef = 9049,
         ERR_RefFieldCannotReferToRefStruct = 9050,
 
+        WRN_AnalyzerReferencesNewerCompiler = 9057,
+
         #endregion
 
         // Note: you will need to re-generate compiler code after adding warnings (eng\generate-compiler-code.cmd)

src/Compilers/CSharp/Portable/Errors/ErrorFacts.cs

@@ -499,6 +499,7 @@ internal static int GetWarningLevel(ErrorCode code)
                 case ErrorCode.WRN_UnassignedThisAutoPropertySupportedVersion:
                 case ErrorCode.WRN_UnassignedThisSupportedVersion:
                 case ErrorCode.WRN_ObsoleteMembersShouldNotBeRequired:
+                case ErrorCode.WRN_AnalyzerReferencesNewerCompiler:
                     return 1;
                 default:
                     return 0;

src/Compilers/CSharp/Portable/Errors/MessageProvider.cs

@@ -178,6 +178,7 @@ internal override bool ShouldAssertExpectedMessageArgumentsLength(int errorCode)
         public override int WRN_NoAnalyzerInAssembly => (int)ErrorCode.WRN_NoAnalyzerInAssembly;
         public override int WRN_UnableToLoadAnalyzer => (int)ErrorCode.WRN_UnableToLoadAnalyzer;
         public override int WRN_AnalyzerReferencesFramework => (int)ErrorCode.WRN_AnalyzerReferencesFramework;
+        public override int WRN_AnalyzerReferencesNewerCompiler => (int)ErrorCode.WRN_AnalyzerReferencesNewerCompiler;
         public override int INF_UnableToLoadSomeTypesInAnalyzer => (int)ErrorCode.INF_UnableToLoadSomeTypesInAnalyzer;
         public override int ERR_CantReadRulesetFile => (int)ErrorCode.ERR_CantReadRulesetFile;
         public override int ERR_CompileCancelled => (int)ErrorCode.ERR_CompileCancelled;