Improve CS9105 in static context

src/Compilers/CSharp/Portable/Binder/Binder_Expressions.cs

@@ -2086,7 +2086,16 @@ private BoundExpression BindNonMethod(SimpleNameSyntax node, Symbol symbol, Bind
                              (this.ContainingMember() is MethodSymbol { MethodKind: MethodKind.Constructor } containingMember && (object)containingMember != primaryCtor)) && // We are in a non-primary instance constructor
                             !IsInsideNameof)
                         {
-                            Error(diagnostics, ErrorCode.ERR_InvalidPrimaryConstructorParameterReference, node, parameter);
+                            // Give a better error for the simple case of using a primary constructor parameter in a static member
+                            if (this.ContainingMember() is { IsStatic: true } && !InParameterDefaultValue && !InAttributeArgument &&
+                                (object)this.ContainingMember().ContainingSymbol == primaryCtor.ContainingSymbol)
+                            {
+                                Error(diagnostics, ErrorCode.ERR_PrimaryConstructorParameterInStaticContext, node, parameter.Name);
+                            }
+                            else
+                            {
+                                Error(diagnostics, ErrorCode.ERR_InvalidPrimaryConstructorParameterReference, node, parameter);
+                            }
                         }
                         else if (parameter.IsExtensionParameter() &&
                                 (InParameterDefaultValue || InAttributeArgument ||

src/Compilers/CSharp/Portable/CSharpResources.resx

@@ -8238,4 +8238,7 @@ To remove the warning, you can use /reference instead (set the Embed Interop Typ
     <value>'{0}' does not contain a definition for '{1}' and no accessible extension method '{1}' accepting a first argument of type '{0}' could be found (did you mean to iterate over the async collection with 'await foreach' instead?)</value>
     <comment>'await foreach' is not localizable</comment>
   </data>
+  <data name="ERR_PrimaryConstructorParameterInStaticContext" xml:space="preserve">
+    <value>Cannot use primary constructor parameter '{0}' in a static member.</value>
+  </data>
 </root>

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

@@ -2462,6 +2462,7 @@ internal enum ErrorCode
         ERR_CollectionArgumentsMustBeEmpty = 9357,
         ERR_CollectionRefLikeElementType = 9358,
         ERR_BadCollectionArgumentsArgCount = 9359,
+        ERR_PrimaryConstructorParameterInStaticContext = 9360,
 
         // Note: you will need to do the following after adding errors:
         //  1) Update ErrorFacts.IsBuildOnlyDiagnostic (src/Compilers/CSharp/Portable/Errors/ErrorFacts.cs)

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

@@ -2346,6 +2346,7 @@ or ErrorCode.ERR_UnscopedRefAttributeUnsupportedMemberTarget
                 or ErrorCode.ERR_UnscopedRefAttributeInterfaceImplementation
                 or ErrorCode.ERR_UnrecognizedRefSafetyRulesAttributeVersion
                 or ErrorCode.ERR_InvalidPrimaryConstructorParameterReference
+                or ErrorCode.ERR_PrimaryConstructorParameterInStaticContext
                 or ErrorCode.ERR_AmbiguousPrimaryConstructorParameterAsColorColorReceiver
                 or ErrorCode.WRN_CapturedPrimaryConstructorParameterPassedToBase
                 or ErrorCode.WRN_UnreadPrimaryConstructorParameter