[turbofan] Remove unsafe JSToBoolean lowering.

test/unittests/compiler/js-typed-lowering-unittest.cc

 // Copyright 2014 the V8 project authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "src/compiler/js-typed-lowering.h"
 #include "src/code-factory.h"
 #include "src/compilation-dependencies.h"
 #include "src/compiler/access-builder.h"
 #include "src/compiler/js-graph.h"
 #include "src/compiler/js-operator.h"
@@ skipping 98 matching lines @@
 
 TEST_F(JSTypedLoweringTest, JSToBooleanWithNumber) {
   Node* input = Parameter(Type::Number(), 0);
   Node* context = Parameter(Type::Any(), 1);
   Reduction r = Reduce(graph()->NewNode(
       javascript()->ToBoolean(ToBooleanHint::kAny), input, context));
   ASSERT_TRUE(r.Changed());
   EXPECT_THAT(r.replacement(), IsNumberToBoolean(input));
 }
 
-TEST_F(JSTypedLoweringTest, JSToBooleanWithString) {
-  Node* input = Parameter(Type::String(), 0);
-  Node* context = Parameter(Type::Any(), 1);
-  Reduction r = Reduce(graph()->NewNode(
-      javascript()->ToBoolean(ToBooleanHint::kAny), input, context));
-  ASSERT_TRUE(r.Changed());
-  EXPECT_THAT(
-      r.replacement(),
-      IsNumberLessThan(IsNumberConstant(0.0),
-                       IsLoadField(AccessBuilder::ForStringLength(), input,
-                                   graph()->start(), graph()->start())));
-}
-
-
 TEST_F(JSTypedLoweringTest, JSToBooleanWithAny) {
   Node* input = Parameter(Type::Any(), 0);
   Node* context = Parameter(Type::Any(), 1);
   Reduction r = Reduce(graph()->NewNode(
       javascript()->ToBoolean(ToBooleanHint::kAny), input, context));
   ASSERT_FALSE(r.Changed());
 }
 
 
 // -----------------------------------------------------------------------------
@@ skipping 878 matching lines @@
                                         EmptyFrameState(), effect, control));
   ASSERT_TRUE(r.Changed());
   EXPECT_THAT(r.replacement(), IsSpeculativeNumberBitwiseXor(
                                    NumberOperationHint::kNumberOrOddball, lhs,
                                    rhs, effect, control));
 }
 
 }  // namespace compiler
 }  // namespace internal
 }  // namespace v8