[interpreter] Partially revert handling of --debug-code.

This is a partial revert of 438c5eb2 to avoid huge increases in
testing times due to expensive bytecode handler generation in debug
modes. The additional coverage does not warrant a 2x to 3x increase
in testing time at the moment. We can revisit this later.

TBR=rmcilroy@chromium.org
NOTREECHECKS=true
NOTRY=true

Review-Url: https://codereview.chromium.org/2445403002
Cr-Commit-Position: refs/heads/master@{#40558}

src/interpreter/interpreter.cc

@@ -223,10 +223,9 @@ bool Interpreter::IsDispatchTableInitialized() {
 
 bool Interpreter::ShouldInitializeDispatchTable() {
   if (FLAG_trace_ignition || FLAG_trace_ignition_codegen ||
-      FLAG_trace_ignition_dispatches || FLAG_debug_code) {
+      FLAG_trace_ignition_dispatches) {
     // Regenerate table to add bytecode tracing operations, print the assembly
-    // code generated by TurboFan, instrument handlers with dispatch counters,
-    // or insert debugging code into the bytecode handlers.
+    // code generated by TurboFan or instrument handlers with dispatch counters.
     return true;
   }
   return !IsDispatchTableInitialized();