fix dead code warning in ComPtr, update natvis

crates/libs/result/.natvis

@@ -1,17 +1,22 @@
 <?xml version="1.0" encoding="utf-8"?>
 <AutoVisualizer xmlns="http://schemas.microsoft.com/vstudio/debugger/natvis/2010">
   <Type Name="windows_result::error::Error">
+    <DisplayString>{(HRESULT)code.__0.__0}</DisplayString>
     <Expand>
       <ExpandedItem>code</ExpandedItem>
-      <Item Name="[detail]">detail</Item>
+      <Item Name="[code]">(HRESULT)code.__0.__0</Item>
+      <Item Name="[info]">info</Item>
     </Expand>
   </Type>
 
   <Type Name="windows_result::hresult::HRESULT">
-    <DisplayString>{(::HRESULT)__0}</DisplayString>
+    <DisplayString>{(HRESULT)__0}</DisplayString>
   </Type>
 
-  <Type Name="windows_result::hresult::NonZeroHRESULT">
-    <DisplayString>{(::HRESULT)__0.__0.__0}</DisplayString>
+  <Type Name="windows_result::error::error_info::ErrorInfo">
+    <DisplayString>ErrorInfo</DisplayString>
+    <Expand>
+      <Item Name="[object]">*(void**)&amp;ptr</Item>
+    </Expand>
   </Type>
 </AutoVisualizer>

crates/libs/result/src/error.rs

@@ -354,10 +354,14 @@ mod error_info {
 mod error_info {
     use super::*;
 
+    // We use this name so that the NatVis <Type> element for ErrorInfo does *not* match this type.
+    // This prevents the NatVis description from failing to load.
     #[derive(Clone, Default)]
-    pub(crate) struct ErrorInfo;
+    pub(crate) struct EmptyErrorInfo;
 
-    impl ErrorInfo {
+    pub(crate) use EmptyErrorInfo as ErrorInfo;
+
+    impl EmptyErrorInfo {
         pub(crate) const fn empty() -> Self {
             Self
         }

crates/libs/result/src/lib.rs

@@ -17,7 +17,7 @@ use alloc::{string::String, vec::Vec};
 mod bindings;
 use bindings::*;
 
-#[cfg(windows)]
+#[cfg(all(windows, feature = "error-info", not(feature = "disable-error-info")))]
 mod com;
 
 #[cfg(windows)]