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

src/platform-cygwin.cc

Index: src/platform-cygwin.cc
===================================================================
--- src/platform-cygwin.cc	(revision 10367)
+++ src/platform-cygwin.cc	(working copy)
@@ -61,7 +61,7 @@
 static Mutex* limit_mutex = NULL;
 
 
-void OS::Setup() {
+void OS::SetUp() {
   // Seed the random number generator.
   // Convert the current time to a 64-bit integer first, before converting it
   // to an unsigned. Going directly can cause an overflow and the seed to be
@@ -290,7 +290,7 @@
       }
       LOG(isolate, SharedLibraryEvent(lib_name, start, end));
     } else {
-      // Entry not describing executable data. Skip to end of line to setup
+      // Entry not describing executable data. Skip to end of line to set up
       // reading the next entry.
       do {
         c = getc(fp);