Fix ResolveGCInfo missing eman/cbh declarations

The ResolveGCInfo helper method referenced eman (IExecutionManager) and
cbh (CodeBlockHandle) without declaring them as local variables.
Add the necessary variable declarations to resolve the build break.

Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>

Author: Max Charlamb

src/native/managed/cdac/Microsoft.Diagnostics.DataContractReader.Legacy/SOSDacImpl.cs

@@ -7390,11 +7390,14 @@ int ISOSDacInterface17.GetStressLogMemoryRanges(DacComNullableByRef<ISOSMemoryEn
 
     private (Contracts.IGCInfoHandle handle, Contracts.IGCInfo gcInfo) ResolveGCInfo(ClrDataAddress ip)
     {
+        IExecutionManager eman = _target.Contracts.ExecutionManager;
+        TargetCodePointer targetCodePointer = ip.ToTargetCodePointer(_target);
+        CodeBlockHandle? cbh = eman.GetCodeBlockHandle(targetCodePointer);
         if (cbh is null)
             throw new ArgumentException("No code block found for the given IP");
 
         eman.GetGCInfo(cbh.Value, out TargetPointer pGcInfo, out uint gcVersion);
-        Contracts.CodeKind codeKind = eman.GetCodeKind(ip.ToTargetCodePointer(_target));
+        Contracts.CodeKind codeKind = eman.GetCodeKind(targetCodePointer);
         Contracts.IGCInfo gcInfo = _target.Contracts.GCInfo;
         Contracts.IGCInfoHandle handle = codeKind == Contracts.CodeKind.Interpreter
             ? gcInfo.DecodeInterpreterGCInfo(pGcInfo, gcVersion)