Backflow from https://github.com/dotnet/dotnet / 5c3434d build 279843

[[ commit created by automation ]]

Author: dotnet-maestro[bot]

src/Shared/RoslynUtils/SymbolExtensions.cs

@@ -231,7 +231,7 @@ private static string InnerGetDefaultValueString(object? defaultValue, ITypeSymb
             double d when d is double.PositiveInfinity => "double.PositiveInfinity",
             double d when d is double.NaN => "double.NaN",
             decimal d => $"{SymbolDisplay.FormatPrimitive(d, false, false)}M",
-            _ => SymbolDisplay.FormatPrimitive(defaultValue, false, false),
+            _ => SymbolDisplay.FormatPrimitive(defaultValue, false, false)!,
         };
     }