Fix issue 98506 - Excessive exceptions generated in StackTraceSymbols (#105530)

* Fix issue 98506 - Excessive exceptions generated in StackTraceSymbols

* Code review feedback

Author: Mike McLaughlin

src/libraries/System.Diagnostics.StackTrace/src/System/Diagnostics/StackTraceSymbols.cs

@@ -58,12 +58,11 @@ internal void GetSourceLineInfo(Assembly assembly, string assemblyPath, IntPtr l
             sourceLine = 0;
             sourceColumn = 0;
 
-            MetadataReader? reader = TryGetReader(assembly, assemblyPath, loadedPeAddress, loadedPeSize, isFileLayout, inMemoryPdbAddress, inMemoryPdbSize);
-            if (reader != null)
+            Handle handle = MetadataTokens.Handle(methodToken);
+            if (!handle.IsNil && handle.Kind == HandleKind.MethodDefinition)
             {
-                Handle handle = MetadataTokens.Handle(methodToken);
-
-                if (handle.Kind == HandleKind.MethodDefinition)
+                MetadataReader? reader = TryGetReader(assembly, assemblyPath, loadedPeAddress, loadedPeSize, isFileLayout, inMemoryPdbAddress, inMemoryPdbSize);
+                if (reader != null)
                 {
                     MethodDebugInformationHandle methodDebugHandle = ((MethodDefinitionHandle)handle).ToDebugInformationHandle();
                     MethodDebugInformation methodInfo = reader.GetMethodDebugInformation(methodDebugHandle);