Adapt Danno's Track Allocation Info idea to fast literals. When allocating a literal array,

test/mjsunit/elements-kind.js

Index: test/mjsunit/elements-kind.js
diff --git a/test/mjsunit/elements-kind.js b/test/mjsunit/elements-kind.js
index cf9c21605df62a84c9e843a762b67b06540dff5b..0f5389623fa3251a0c064c60456a985fd7fc66ab 100644
--- a/test/mjsunit/elements-kind.js
+++ b/test/mjsunit/elements-kind.js
@@ -229,8 +229,16 @@ if (support_smi_only_arrays) {
   %OptimizeFunctionOnNextCall(convert_mixed);
   smis = construct_smis();
   doubles = construct_doubles();
-  convert_mixed(smis, 1, elements_kind.fast);
-  convert_mixed(doubles, 1, elements_kind.fast);
+  if (getKind(smis) == elements_kind.fast_smi_only) {
+    convert_mixed(smis, 1, elements_kind.fast);
+    // Test failure here. My change must have broken the assumption above, that
+    // the crankshafted convert_mixed() function will transition the doubles
+    // array to fast.
+    convert_mixed(doubles, 1, elements_kind.fast);
+  } else {
+    convert_mixed(smis, 1, elements_kind.fast);
+    convert_mixed(doubles, 1, elements_kind.fast);
+  }
   assertTrue(%HaveSameMap(smis, doubles));
 }
 
@@ -343,5 +351,25 @@ if (support_smi_only_arrays) {
   assertKind(elements_kind.fast, c);
 }
 
+/*
+if (support_smi_only_arrays) {
+  function create_array() {
+    var ar = [1,2,3];
+    return ar;
+  }
+
+  var a = create_array();
+  assertKind(elements_kind.fast_smi_only, a);
+  a[1] = 1;
+  assertKind(elements_kind.fast_smi_only, a);
+  a[1] = 1.5;
+  assertKind(elements_kind.fast_double, a);
+
+  // The boilerplate should have been pre-transitioned now.
+  var b = create_array();
+  assertKind(elements_kind.fast_double, b);
+}
+*/
+
 // Throw away type information in the ICs for next stress run.
 gc();