Fraction class prototype and test (not to be committed).

runtime/vm/intrinsifier_arm.cc

Index: runtime/vm/intrinsifier_arm.cc
diff --git a/runtime/vm/intrinsifier_arm.cc b/runtime/vm/intrinsifier_arm.cc
index 2daafedeeafe74c9f895d599b153b6769e5c8c24..2397f340b3db7a4d26e40e7e62283039b4fe43cc 100644
--- a/runtime/vm/intrinsifier_arm.cc
+++ b/runtime/vm/intrinsifier_arm.cc
@@ -707,11 +707,14 @@ void Intrinsifier::Integer_equalToInteger(Assembler* assembler) {
   __ tst(R1, Operand(kSmiTagMask));  // Check receiver.
   __ b(&receiver_not_smi, NE);
 
-  // Left (receiver) is Smi, return false if right is not Double.
+  // Left (receiver) is Smi, return false if right is not Double or Fraction.
   // Note that an instance of Mint or Bigint never contains a value that can be
   // represented by Smi.
 
-  __ CompareClassId(R0, kDoubleCid, R2);
+  __ LoadClassId(R2, R0);
+  __ CompareImmediate(R2, kDoubleCid);
+  __ b(&fall_through, EQ);
+  __ CompareImmediate(R2, kFractionCid);
   __ b(&fall_through, EQ);
   __ LoadObject(R0, Bool::False());  // Smi == Mint -> false.
   __ Ret();