Don't use LOG() from platform.

src/platform-cygwin.cc

Index: src/platform-cygwin.cc
diff --git a/src/platform-cygwin.cc b/src/platform-cygwin.cc
index 15a59130d0af3e3e0bfec38d98d4ccee7dd22294..e139775dad322057b8a6aac413903d454a49e89e 100644
--- a/src/platform-cygwin.cc
+++ b/src/platform-cygwin.cc
@@ -53,10 +53,7 @@ void* OS::Allocate(const size_t requested,
   const size_t msize = RoundUp(requested, sysconf(_SC_PAGESIZE));
   int prot = PROT_READ | PROT_WRITE | (is_executable ? PROT_EXEC : 0);
   void* mbase = mmap(NULL, msize, prot, MAP_PRIVATE | MAP_ANONYMOUS, -1, 0);
-  if (mbase == MAP_FAILED) {
-    LOG(Isolate::Current(), StringEvent("OS::Allocate", "mmap failed"));
-    return NULL;
-  }
+  if (mbase == MAP_FAILED) return NULL;
   *allocated = msize;
   return mbase;
 }