[turbofan] Don't call String::Flatten in Constant::ToHeapObject()

src/compiler/instruction.cc

Index: src/compiler/instruction.cc
diff --git a/src/compiler/instruction.cc b/src/compiler/instruction.cc
index 1ef42d6bccee432e02db647cbe9631b8c76e2177..3d281d16f325c90436d22c1bcc4ce03b4133a247 100644
--- a/src/compiler/instruction.cc
+++ b/src/compiler/instruction.cc
@@ -519,9 +519,6 @@ Handle<HeapObject> Constant::ToHeapObject() const {
   DCHECK_EQ(kHeapObject, type());
   Handle<HeapObject> value(
       bit_cast<HeapObject**>(static_cast<intptr_t>(value_)));
-  if (value->IsConsString()) {
-    value = String::Flatten(Handle<String>::cast(value), TENURED);
-  }
   return value;
 }