Cosmetic changes ("set up" is a verb, "setup" is a noun).

src/x64/deoptimizer-x64.cc

Index: src/x64/deoptimizer-x64.cc
===================================================================
--- src/x64/deoptimizer-x64.cc	(revision 10367)
+++ src/x64/deoptimizer-x64.cc	(working copy)
@@ -314,7 +314,7 @@
     output_[0] = input_;
     output_[0]->SetPc(reinterpret_cast<intptr_t>(from_));
   } else {
-    // Setup the frame pointer and the context pointer.
+    // Set up the frame pointer and the context pointer.
     output_[0]->SetRegister(rbp.code(), input_->GetRegister(rbp.code()));
     output_[0]->SetRegister(rsi.code(), input_->GetRegister(rsi.code()));