Target: correct the return value for GetImageAddrFromToken

We would return `LLDB_INVALID_IMAGE_TOKEN` for the address rather than
the correct value of `LLDB_IMAGE_ADDRESS`.  This would result in the
check for the return value to silently pass on x64 as the invalid
address and invalid token are of different sizes (`size_t` vs
`uintprr_t`).  This corrects the return value to `LLDB_INVALID_ADDRESS`
and addresses the rest to reset the mapped address to the invalid value.

This was found by inspection when trying to implement module support for
Windows.

Author: compnerd

lldb/source/Target/Process.cpp

@@ -5796,12 +5796,12 @@ size_t Process::AddImageToken(lldb::addr_t image_ptr) {
 lldb::addr_t Process::GetImagePtrFromToken(size_t token) const {
   if (token < m_image_tokens.size())
     return m_image_tokens[token];
-  return LLDB_INVALID_IMAGE_TOKEN;
+  return LLDB_INVALID_ADDRESS;
 }
 
 void Process::ResetImageToken(size_t token) {
   if (token < m_image_tokens.size())
-    m_image_tokens[token] = LLDB_INVALID_IMAGE_TOKEN;
+    m_image_tokens[token] = LLDB_INVALID_ADDRESS;
 }
 
 Address