Revert "[LibFuzzer] Split FuzzerUtil for Posix and Windows."

This reverts commit r288529, as it seems to introduce some
problems on the Linux bots.

llvm-svn: 288533
diff --git a/llvm/lib/Fuzzer/FuzzerUtil.h b/llvm/lib/Fuzzer/FuzzerUtil.h
index c9de11f..97271b9 100644
--- a/llvm/lib/Fuzzer/FuzzerUtil.h
+++ b/llvm/lib/Fuzzer/FuzzerUtil.h
@@ -40,8 +40,6 @@
 
 int NumberOfCpuCores();
 
-bool ExecuteCommandAndReadOutput(const std::string &Command, std::string *Out);
-
 // Platform specific functions.
 void SetTimer(int Seconds);
 
@@ -59,12 +57,9 @@
 
 size_t GetPeakRSSMb();
 
+bool ExecuteCommandAndReadOutput(const std::string &Command, std::string *Out);
+
 int ExecuteCommand(const std::string &Command);
 
-FILE *OpenProcessPipe(const char *Command, const char *Mode);
-
-const void *SearchMemory(const void *haystack, size_t haystacklen,
-                         const void *needle, size_t needlelen);
-
 }  // namespace fuzzer
 #endif  // LLVM_FUZZER_UTIL_H