[regexp] Teach deoptimizer to materialize JSRegExp objects

Now that literal allocation is inlined, it is possible to optimize out regexp
literal allocation completely. If a lazy deopt is triggered in that situation,
the deoptimizer needs to know how to materialize regexp objects.

Bug: v8:6605,v8:6556,chromium:747825
Change-Id: Id491053f8e64fec16540efbfdc6c7c524da3e080
Reviewed-on: https://chromium-review.googlesource.com/582609Reviewed-by: Jaroslav Sevcik <jarin@chromium.org>
Commit-Queue: Jakob Gruber <jgruber@chromium.org>
Cr-Commit-Position: refs/heads/master@{#46837}

src/deoptimizer.cc

@@ -3835,6 +3835,24 @@ Handle<Object> TranslatedState::MaterializeCapturedObjectAt(
       }
       return object;
     }
+    case JS_REGEXP_TYPE: {
+      Handle<JSRegExp> object = Handle<JSRegExp>::cast(
+          isolate_->factory()->NewJSObjectFromMap(map, NOT_TENURED));
+      slot->value_ = object;
+      Handle<Object> properties = materializer.FieldAt(value_index);
+      Handle<Object> elements = materializer.FieldAt(value_index);
+      Handle<Object> data = materializer.FieldAt(value_index);
+      Handle<Object> source = materializer.FieldAt(value_index);
+      Handle<Object> flags = materializer.FieldAt(value_index);
+      Handle<Object> last_index = materializer.FieldAt(value_index);
+      object->set_raw_properties_or_hash(*properties);
+      object->set_elements(FixedArrayBase::cast(*elements));
+      object->set_data(*data);
+      object->set_source(*source);
+      object->set_flags(*flags);
+      object->set_last_index(*last_index);
+      return object;
+    }
     case STRING_TYPE:
     case ONE_BYTE_STRING_TYPE:
     case CONS_ONE_BYTE_STRING_TYPE:
@@ -3870,7 +3888,6 @@ Handle<Object> TranslatedState::MaterializeCapturedObjectAt(
     case JS_ASYNC_GENERATOR_OBJECT_TYPE:
     case JS_MODULE_NAMESPACE_TYPE:
     case JS_ARRAY_BUFFER_TYPE:
-    case JS_REGEXP_TYPE:
     case JS_TYPED_ARRAY_TYPE:
     case JS_DATA_VIEW_TYPE:
     case JS_SET_TYPE:

test/mjsunit/regress/regress-747825.js

+// Copyright 2017 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.
+
+// Flags: --allow-natives-syntax
+
+var g = 0;
+g = function() {}
+
+function f() {
+  var r = /[abc]/i;  // Optimized out.
+  g(r);
+}
+
+f(); f(); %OptimizeFunctionOnNextCall(f);  // Warm-up.
+
+var re;
+g = function(r) { re = r; }
+f();  // Lazy deopt is forced here.
+
+assertNotEquals(undefined, re);
+assertEquals("[abc]", re.source);
+assertEquals("i", re.flags);
+assertEquals(0, re.lastIndex);
+assertArrayEquals(["a"], re.exec("a"));
+assertArrayEquals(["A"], re.exec("A"));
+assertNull(re.exec("d"));