Previously, the following schedule fragment:

 1: Parameter[0](0)
 2: Parameter[1](0)
 7: Int32Constant[1]
 8: Int32Sub(2, 7)
 9: Load[kRepTagged|kTypeAny](1, 8)

would generate the following code (on ia32):

 mov eax,[ebp+0x8]
 mov ecx,[ebp+0xc]
 sub eax,0x1
 mov eax,[eax+ecx*1]

Now it generates:

 mov eax,[ebp+0x8]
 mov ecx,[ebp+0xc]
 mov eax,[eax+ecx*1-1]

Similar pattern matching also now works on x64.

BUG=v8:5192
LOG=N

Review-Url: https://codereview.chromium.org/2137323003
Cr-Commit-Position: refs/heads/master@{#37701}