message: Fix natvis display for heap-allocated rdcstr capacity
diff: <DisplayString>Heap-allocated String</DisplayString>
  </Synthetic>
  <Item Name="[size]" ExcludeView="simple" Condition="d.fixed.flags &amp; rdcstr::ALLOC_STATE">d.alloc.size</Item>
  - <Item Name="[capacity]" ExcludeView="simple" Condition="d.fixed.flags &amp; rdcstr::ALLOC_STATE">d.alloc._capacity</Item>
  + <Item Name="[capacity]" ExcludeView="simple" Condition="d.fixed.flags &amp; rdcstr::ALLOC_STATE">d.alloc._capacity &amp; rdcstr::alloc_ptr_rep::CAPACITY_MASK</Item>
  <ArrayItems Condition="d.fixed.flags &amp; rdcstr::ALLOC_STATE">
  <Size>d.alloc.size</Size>
  <ValuePointer>d.alloc.str</ValuePointer>
  