[turbofan] Gracefully bail out if OSR encounters a loop too deeply nested.

src/compiler/pipeline.cc

Index: src/compiler/pipeline.cc
diff --git a/src/compiler/pipeline.cc b/src/compiler/pipeline.cc
index ef0144cfe303056a43873db4fd719fa22b8dd609..6e712156faaf245999734e25b689b87b7b446b69 100644
--- a/src/compiler/pipeline.cc
+++ b/src/compiler/pipeline.cc
@@ -414,7 +414,9 @@ struct OsrDeconstructionPhase {
     SourcePositionTable::Scope pos(data->source_positions(),
                                    SourcePosition::Unknown());
     OsrHelper osr_helper(data->info());
-    osr_helper.Deconstruct(data->jsgraph(), data->common(), temp_zone);
+    bool success =
+        osr_helper.Deconstruct(data->jsgraph(), data->common(), temp_zone);
+    if (!success) data->info()->RetryOptimization(kOsrCompileFailed);
   }
 };
 
@@ -774,8 +776,11 @@ void Pipeline::RunPrintAndVerify(const char* phase, bool untyped) {
 
 
 Handle<Code> Pipeline::GenerateCode() {
-  // TODO(turbofan): Make OSR work with inner loops and remove this bailout.
-  if (info()->is_osr() && !FLAG_turbo_osr) return Handle<Code>::null();
+  if (info()->is_osr() && !FLAG_turbo_osr) {
+    // TODO(turbofan): remove this flag and always handle OSR
+    info()->RetryOptimization(kOsrCompileFailed);
+    return Handle<Code>::null();
+  }
 
   // TODO(mstarzinger): This is just a temporary hack to make TurboFan work,
   // the correct solution is to restore the context register after invoking
@@ -863,6 +868,7 @@ Handle<Code> Pipeline::GenerateCode() {
 
     if (info()->is_osr()) {
       Run<OsrDeconstructionPhase>();
+      if (info()->bailout_reason() != kNoReason) return Handle<Code>::null();
       RunPrintAndVerify("OSR deconstruction");
     }
 
@@ -880,6 +886,7 @@ Handle<Code> Pipeline::GenerateCode() {
   } else {
     if (info()->is_osr()) {
       Run<OsrDeconstructionPhase>();
+      if (info()->bailout_reason() != kNoReason) return Handle<Code>::null();
       RunPrintAndVerify("OSR deconstruction");
     }
   }