x86/x64 port of Math.floor(x/y) to use integer division for specific divisor

src/hydrogen-instructions.h

Index: src/hydrogen-instructions.h
===================================================================
--- src/hydrogen-instructions.h	(revision 11883)
+++ src/hydrogen-instructions.h	(working copy)
@@ -2774,8 +2774,11 @@
       : HBinaryOperation(context, left, right) {
     set_representation(Representation::Integer32());
     SetFlag(kUseGVN);
+    SetFlag(kCanOverflow);
   }
 
+  virtual HValue* EnsureAndPropagateNotMinusZero(BitVector* visited);
+
   virtual Representation RequiredInputRepresentation(int index) {
     return Representation::Integer32();
   }