Merge bleeding edge into the GC branch up to 7948. The asserts

src/lithium.cc

Index: src/lithium.cc
===================================================================
--- src/lithium.cc	(revision 7948)
+++ src/lithium.cc	(working copy)
@@ -187,4 +187,25 @@
 }
 
 
+int ExternalArrayTypeToShiftSize(ExternalArrayType type) {
+  switch (type) {
+    case kExternalByteArray:
+    case kExternalUnsignedByteArray:
+    case kExternalPixelArray:
+      return 0;
+    case kExternalShortArray:
+    case kExternalUnsignedShortArray:
+      return 1;
+    case kExternalIntArray:
+    case kExternalUnsignedIntArray:
+    case kExternalFloatArray:
+      return 2;
+    case kExternalDoubleArray:
+      return 3;
+  }
+  UNREACHABLE();
+  return 0;
+}
+
+
 } }  // namespace v8::internal