Revert of [turbofan] Remove the leftover LoadBuffer hacks.

src/compiler/change-lowering.cc

Index: src/compiler/change-lowering.cc
diff --git a/src/compiler/change-lowering.cc b/src/compiler/change-lowering.cc
index 7f6cd6beda6a83d7480f5d62154e475d04e72371..cb5d0eb033b4602fc085766478a778c4dc59ec8f 100644
--- a/src/compiler/change-lowering.cc
+++ b/src/compiler/change-lowering.cc
@@ -175,9 +175,12 @@
   Type* const value_type = NodeProperties::GetType(value);
   Node* const value32 = graph()->NewNode(
       machine()->TruncateFloat64ToInt32(TruncationMode::kRoundToZero), value);
-  if (value_type->Is(Type::Signed32())) {
-    return ChangeInt32ToTagged(value32, control);
-  }
+  // TODO(bmeurer): This fast case must be disabled until we kill the asm.js
+  // support in the generic JavaScript pipeline, because LoadBuffer is lying
+  // about its result.
+  // if (value_type->Is(Type::Signed32())) {
+  //   return ChangeInt32ToTagged(value32, control);
+  // }
   Node* check_same = graph()->NewNode(
       machine()->Float64Equal(), value,
       graph()->NewNode(machine()->ChangeInt32ToFloat64(), value32));