[LibFuzzer] Split FuzzerUtil for Posix and Windows.

Pave the way for separating out platform specific
utility functions into separate files.

Patch by Marcos Pividori
Differential Revision: https://reviews.llvm.org/D27234

llvm-svn: 288529
diff --git a/llvm/lib/Fuzzer/FuzzerUtil.h b/llvm/lib/Fuzzer/FuzzerUtil.h
index 97271b9..c9de11f 100644
--- a/llvm/lib/Fuzzer/FuzzerUtil.h
+++ b/llvm/lib/Fuzzer/FuzzerUtil.h
@@ -40,6 +40,8 @@
 
 int NumberOfCpuCores();
 
+bool ExecuteCommandAndReadOutput(const std::string &Command, std::string *Out);
+
 // Platform specific functions.
 void SetTimer(int Seconds);
 
@@ -57,9 +59,12 @@
 
 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