Delete dead code.

lib/SILOptimizer/Utils/SILIsolationInfo.cpp

@@ -53,102 +53,6 @@ getGlobalActorInitIsolation(SILFunction *fn) {
   return getActorIsolation(globalDecl);
 }
 
-class DeclRefExprAnalysis {
-  DeclRefExpr *result = nullptr;
-
-  // Be greedy with the small size so we very rarely allocate.
-  SmallVector<Expr *, 8> lookThroughExprs;
-
-public:
-  bool compute(Expr *expr);
-
-  DeclRefExpr *getResult() const {
-    assert(result && "Not computed?!");
-    return result;
-  }
-
-  ArrayRef<Expr *> getLookThroughExprs() const {
-    assert(result && "Not computed?!");
-    return lookThroughExprs;
-  }
-
-  void print(llvm::raw_ostream &os) const {
-    if (!result) {
-      os << "DeclRefExprAnalysis: None.";
-      return;
-    }
-
-    os << "DeclRefExprAnalysis:\n";
-    result->dump(os);
-    os << "\n";
-    if (lookThroughExprs.size()) {
-      os << "LookThroughExprs:\n";
-      for (auto *expr : lookThroughExprs) {
-        expr->dump(os, 4);
-      }
-    }
-  }
-
-  SWIFT_DEBUG_DUMP { print(llvm::dbgs()); }
-
-  bool hasNonisolatedUnsafe() const {
-    // See if our initial member_ref_expr is actor instance isolated.
-    for (auto *expr : lookThroughExprs) {
-      // We can skip load expr.
-      if (isa<LoadExpr>(expr))
-        continue;
-
-      if (auto *mri = dyn_cast<MemberRefExpr>(expr)) {
-        if (mri->hasDecl()) {
-          auto isolation = swift::getActorIsolation(mri->getDecl().getDecl());
-          if (isolation.isNonisolatedUnsafe())
-            return true;
-        }
-      }
-
-      break;
-    }
-
-    return false;
-  }
-};
-
-bool DeclRefExprAnalysis::compute(Expr *expr) {
-  struct LocalWalker final : ASTWalker {
-    DeclRefExprAnalysis &parentAnalysis;
-
-    LocalWalker(DeclRefExprAnalysis &parentAnalysis)
-        : parentAnalysis(parentAnalysis) {}
-
-    PreWalkResult<Expr *> walkToExprPre(Expr *expr) override {
-      assert(!parentAnalysis.result && "Shouldn't have a result yet");
-
-      if (auto *dre = dyn_cast<DeclRefExpr>(expr)) {
-        parentAnalysis.result = dre;
-        return Action::Stop();
-      }
-
-      if (isa<CoerceExpr, MemberRefExpr, ImplicitConversionExpr, IdentityExpr>(
-              expr)) {
-        parentAnalysis.lookThroughExprs.push_back(expr);
-        return Action::Continue(expr);
-      }
-
-      return Action::Stop();
-    }
-  };
-
-  LocalWalker walker(*this);
-
-  if (auto *ae = dyn_cast<AssignExpr>(expr)) {
-    ae->getSrc()->walk(walker);
-  } else {
-    expr->walk(walker);
-  }
-
-  return result;
-}
-
 static SILIsolationInfo
 inferIsolationInfoForTempAllocStack(AllocStackInst *asi) {
   // We want to search for an alloc_stack that is not from a VarDecl and that is