Improve legibility of conditional

Commit bceb817 made the following edits:

```
   SILDeclRef method = i->getMember().getOverriddenVTableEntry();
   auto methodType = i->getType().castTo<SILFunctionType>();

+  AccessLevel methodAccess = method.getDecl()->getEffectiveAccess();
   auto *classDecl = cast<ClassDecl>(method.getDecl()->getDeclContext());
   bool shouldUseDispatchThunk = false;
-  if (IGM.hasResilientMetadata(classDecl, ResilienceExpansion::Maximal)) {
+  // Because typechecking for the debugger has more lax rules, check the access
+  // level of the getter to decide whether to use a dispatch thunk for the
+  // debugger.
+  bool shouldUseDispatchThunkIfInDebugger =
+      !classDecl->getASTContext().LangOpts.DebuggerSupport ||
+      methodAccess == AccessLevel::Public;
+  if (IGM.hasResilientMetadata(classDecl, ResilienceExpansion::Maximal) &&
+      shouldUseDispatchThunkIfInDebugger) {
     shouldUseDispatchThunk = true;
   } else if (IGM.getOptions().VirtualFunctionElimination) {
     // For VFE, use a thunk if the target class is in another module. This
```

This commit refactors the conditional that make it more obvious that
only the LLDB code path is meant to be affected.

Author: adrian-prantl

lib/IRGen/IRGenSIL.cpp

@@ -8432,9 +8432,9 @@ void IRGenSILFunction::visitClassMethodInst(swift::ClassMethodInst *i) {
   // level of the getter to decide whether to use a dispatch thunk for the
   // debugger.
   bool shouldUseDispatchThunkIfInDebugger =
-      !classDecl->getASTContext().LangOpts.DebuggerSupport ||
+      classDecl->getASTContext().LangOpts.DebuggerSupport &&
       methodAccess >= AccessLevel::Public;
-  if (IGM.hasResilientMetadata(classDecl, ResilienceExpansion::Maximal) &&
+  if (IGM.hasResilientMetadata(classDecl, ResilienceExpansion::Maximal) ||
       shouldUseDispatchThunkIfInDebugger) {
     shouldUseDispatchThunk = true;
   } else if (IGM.getOptions().VirtualFunctionElimination) {