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

runtime/vm/intrinsifier_ia32.cc

Index: runtime/vm/intrinsifier_ia32.cc
diff --git a/runtime/vm/intrinsifier_ia32.cc b/runtime/vm/intrinsifier_ia32.cc
index b9ea3a19f671a6678add2fa67f781d6402924614..f46e7d0e93819c95f3f13ac68a245b4c77d940c5 100644
--- a/runtime/vm/intrinsifier_ia32.cc
+++ b/runtime/vm/intrinsifier_ia32.cc
@@ -736,11 +736,14 @@ void Intrinsifier::Integer_equalToInteger(Assembler* assembler) {
   __ testl(EAX, Immediate(kSmiTagMask));
   __ j(NOT_ZERO, &receiver_not_smi);
 
-  // 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.
   __ movl(EAX, Address(ESP, + 1 * kWordSize));  // Right argument.
-  __ CompareClassId(EAX, kDoubleCid, EDI);
+  __ LoadClassId(EDI, EAX);
+  __ cmpl(EDI, Immediate(kDoubleCid));
+  __ j(EQUAL, &fall_through);
+  __ cmpl(EDI, Immediate(kFractionCid));
   __ j(EQUAL, &fall_through);
   __ LoadObject(EAX, Bool::False());  // Smi == Mint -> false.
   __ ret();