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

src/x64/assembler-x64.cc

Index: src/x64/assembler-x64.cc
===================================================================
--- src/x64/assembler-x64.cc	(revision 10367)
+++ src/x64/assembler-x64.cc	(working copy)
@@ -383,7 +383,7 @@
   }
 #endif
 
-  // Setup buffer pointers.
+  // Set up buffer pointers.
   ASSERT(buffer_ != NULL);
   pc_ = buffer_;
   reloc_info_writer.Reposition(buffer_ + buffer_size, pc_);
@@ -412,7 +412,7 @@
   // Finalize code (at this point overflow() may be true, but the gap ensures
   // that we are still not overlapping instructions and relocation info).
   ASSERT(pc_ <= reloc_info_writer.pos());  // No overlap.
-  // Setup code descriptor.
+  // Set up code descriptor.
   desc->buffer = buffer_;
   desc->buffer_size = buffer_size_;
   desc->instr_size = pc_offset();
@@ -502,7 +502,7 @@
     V8::FatalProcessOutOfMemory("Assembler::GrowBuffer");
   }
 
-  // Setup new buffer.
+  // Set up new buffer.
   desc.buffer = NewArray<byte>(desc.buffer_size);
   desc.instr_size = pc_offset();
   desc.reloc_size =