Fix ARM external array crankshaft bailout

BUG=none
TEST=none

Review URL: http://codereview.chromium.org/6730054

git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@7362 ce2b1a6d-e550-0410-aec6-3dcde31c8c00

src/arm/lithium-arm.cc

@@ -1827,6 +1827,7 @@ LInstruction* LChunkBuilder::DoLoadKeyedSpecializedArrayElement(
   // TODO(danno): Add support for other external array types.
   if (instr->array_type() != kExternalPixelArray) {
     Abort("unsupported load for external array type.");
+    return NULL;
   }
 
   ASSERT(instr->representation().IsInteger32());
@@ -1875,6 +1876,7 @@ LInstruction* LChunkBuilder::DoStoreKeyedSpecializedArrayElement(
   // TODO(danno): Add support for other external array types.
   if (instr->array_type() != kExternalPixelArray) {
     Abort("unsupported store for external array type.");
+    return NULL;
   }
 
   ASSERT(instr->value()->representation().IsInteger32());