Fix a race condition in getting the process exit code on Win32.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@77953 91177308-0d34-0410-b5e6-96231b3b80d8

lib/System/Unix/Program.inc

@@ -35,6 +35,10 @@
 namespace llvm {
 using namespace sys;
 
+Program::Program() : Pid_(0) {}
+
+Program::~Program() {}
+
 // This function just uses the PATH environment variable to find the program.
 Path
 Program::FindProgramByName(const std::string& progName) {