[lldb][Expression][NFC] Make LoadAddressResolver::m_target a reference (llvm#149490)

The only place that passes a target to `LoadAddressResolver` already
checks for pointer validity. And inside of the resolver we have been
dereferencing the target anyway without nullptr checks. So codify the
non-nullness of `m_target` by making it a reference.

(cherry picked from commit 03b7766)

Author: Michael137

lldb/source/Expression/IRExecutionUnit.cpp

@@ -742,7 +742,7 @@ void IRExecutionUnit::CollectCandidateCPlusPlusNames(
 
 class LoadAddressResolver {
 public:
-  LoadAddressResolver(Target *target, bool &symbol_was_missing_weak)
+  LoadAddressResolver(Target &target, bool &symbol_was_missing_weak)
       : m_target(target), m_symbol_was_missing_weak(symbol_was_missing_weak) {}
 
   std::optional<lldb::addr_t> Resolve(SymbolContextList &sc_list) {
@@ -764,20 +764,20 @@ class LoadAddressResolver {
 
       // First try the symbol.
       if (candidate_sc.symbol) {
-        load_address = candidate_sc.symbol->ResolveCallableAddress(*m_target);
+        load_address = candidate_sc.symbol->ResolveCallableAddress(m_target);
         if (load_address == LLDB_INVALID_ADDRESS) {
           Address addr = candidate_sc.symbol->GetAddress();
-          load_address = m_target->GetProcessSP()
-                             ? addr.GetLoadAddress(m_target)
+          load_address = m_target.GetProcessSP()
+                             ? addr.GetLoadAddress(&m_target)
                              : addr.GetFileAddress();
         }
       }
 
       // If that didn't work, try the function.
       if (load_address == LLDB_INVALID_ADDRESS && candidate_sc.function) {
         Address addr = candidate_sc.function->GetAddress();
-        load_address = m_target->GetProcessSP() ? addr.GetLoadAddress(m_target)
-                                                : addr.GetFileAddress();
+        load_address = m_target.GetProcessSP() ? addr.GetLoadAddress(&m_target)
+                                               : addr.GetFileAddress();
       }
 
       // We found a load address.
@@ -808,7 +808,7 @@ class LoadAddressResolver {
   }
 
 private:
-  Target *m_target;
+  Target &m_target;
   bool &m_symbol_was_missing_weak;
   lldb::addr_t m_best_internal_load_address = LLDB_INVALID_ADDRESS;
 };
@@ -866,7 +866,7 @@ IRExecutionUnit::FindInSymbols(const std::vector<ConstString> &names,
   for (size_t i = 0; i < m_preferred_modules.GetSize(); ++i)
     non_local_images.Remove(m_preferred_modules.GetModuleAtIndex(i));
 
-  LoadAddressResolver resolver(target, symbol_was_missing_weak);
+  LoadAddressResolver resolver(*target, symbol_was_missing_weak);
 
   ModuleFunctionSearchOptions function_options;
   function_options.include_symbols = true;