Const-correctness.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@81249 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/System/Win32/Program.inc b/lib/System/Win32/Program.inc
index b23fdce..87f9e64 100644
--- a/lib/System/Win32/Program.inc
+++ b/lib/System/Win32/Program.inc
@@ -35,7 +35,7 @@
   }
 }
 
-unsigned Program::GetPid() {
+unsigned Program::GetPid() const {
   HANDLE hProcess = reinterpret_cast<HANDLE>(Data_);
   return GetProcessId(hProcess);
 }