Port and integrate the irregexp engine from V8

runtime/vm/raw_object.h

Index: runtime/vm/raw_object.h
diff --git a/runtime/vm/raw_object.h b/runtime/vm/raw_object.h
index 9e48fac0af64fcdb95096cdfdd6d3ce973a789c2..1b446d189d702b0bf0f65c1162f512156f3dfc40 100644
--- a/runtime/vm/raw_object.h
+++ b/runtime/vm/raw_object.h
@@ -631,6 +631,7 @@ class RawFunction : public RawObject {
     kMethodExtractor,  // converts method into implicit closure on the receiver.
     kNoSuchMethodDispatcher,  // invokes noSuchMethod.
     kInvokeFieldDispatcher,  // invokes a field as a closure.
+    kIrregexpFunction,   // represents a generated irregexp matcher function.
   };
 
   enum AsyncModifier {
@@ -673,6 +674,7 @@ class RawFunction : public RawObject {
   int16_t num_fixed_parameters_;
   int16_t num_optional_parameters_;  // > 0: positional; < 0: named.
   int16_t deoptimization_counter_;
+  int16_t regexp_cid_;

[Ivan Posva, 2014/10/10 06:35:54]

Would an int8_t do? Or a uint8_t?

Generally it is a bad idea to add fields to RawFunction, as every field added
causes significant memory consumption.

It does not appear that this field is ever being properly preserved into or
initialized from a snapshot.

Also these fields should be sorted by size, so that we do not end up with
internal alignment. Not your CL's issue though.

[Vyacheslav Egorov (Google), 2014/10/10 08:08:08]

We were indeed concerned about the size of the Function (if you go back through
comments you will see that I was against adding any fields to it).

However here I counted the fields and saw that we have 16bits ununused - so this
field does not really increase any memory consumption.

I have a backup plan on how to *not* add this field  - which we will apply if
somebody else needs 16bits in Function. The only reason we did not apply it
right away was that it makes current CL even bigger.
Great catch with a snapshot. Really easy to forget with the current setup, and
it's not caught statically.

[jgruber1, 2014/10/10 09:29:44]

Added snapshotting of regexp_cid_.

   uint32_t kind_tag_;  // See Function::KindTagBits.
   uint16_t optimized_instruction_count_;
   uint16_t optimized_call_site_count_;
@@ -1768,8 +1770,12 @@ class RawJSRegExp : public RawInstance {
   RawSmi* data_length_;
   RawSmi* num_bracket_expressions_;
   RawString* pattern_;  // Pattern to be used for matching.
+  RawFunction* one_byte_function_;
+  RawFunction* two_byte_function_;
+  RawFunction* external_one_byte_function_;
+  RawFunction* external_two_byte_function_;
   RawObject** to() {
-    return reinterpret_cast<RawObject**>(&ptr()->pattern_);
+    return reinterpret_cast<RawObject**>(&ptr()->external_two_byte_function_);
   }
 
   // A bitfield with two fields: