Initial SIMDBC interpreter.

runtime/vm/dart_entry.h

Index: runtime/vm/dart_entry.h
diff --git a/runtime/vm/dart_entry.h b/runtime/vm/dart_entry.h
index 0f9597f418955d9892c056f0c55911cca811e307..8c530ea6c474a375cc56b3a49bef1a25120b7433 100644
--- a/runtime/vm/dart_entry.h
+++ b/runtime/vm/dart_entry.h
@@ -86,6 +86,19 @@ class ArgumentsDescriptor : public ValueObject {
 
   static RawArray* NewNonCached(intptr_t count, bool canonicalize = true);
 
+  // Used by Simulator to parse argument descriptors.
+  static intptr_t name_index(intptr_t index) {
+    return kFirstNamedEntryIndex +
+           (index * kNamedEntrySize) +
+           kNameOffset;
+  }
+
+  static intptr_t position_index(intptr_t index) {
+    return kFirstNamedEntryIndex +
+           (index * kNamedEntrySize) +
+           kPositionOffset;
+  }
+
   const Array& array_;
 
   // A cache of VM heap allocated arguments descriptors.
@@ -93,6 +106,7 @@ class ArgumentsDescriptor : public ValueObject {
 
   friend class SnapshotReader;
   friend class SnapshotWriter;
+  friend class Simulator;

[zra, 2016/04/08 22:37:34]

Any reason not to make the added functions public?

[Vyacheslav Egorov (Google), 2016/04/11 10:49:10]

Simulator also accesses kPositionalCountIndex which is private. We can make
everything public. 

   DISALLOW_COPY_AND_ASSIGN(ArgumentsDescriptor);
 };