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

src/hydrogen-instructions.cc

Index: src/hydrogen-instructions.cc
===================================================================
--- src/hydrogen-instructions.cc	(revision 11872)
+++ src/hydrogen-instructions.cc	(working copy)
@@ -941,7 +941,8 @@
     // introduced.
     if (value()->representation().IsInteger32()) return value();
 
-#ifdef V8_TARGET_ARCH_ARM
+#if defined(V8_TARGET_ARCH_ARM) || defined(V8_TARGET_ARCH_IA32) || \
+        defined(V8_TARGET_ARCH_X64)
     if (value()->IsDiv() && (value()->UseCount() == 1)) {
       // TODO(2038): Implement this optimization for non ARM architectures.
       HDiv* hdiv = HDiv::cast(value());