Rebased PNaCl localmods in LLVM to 223109

lib/Support/Unix/Process.inc

Index: lib/Support/Unix/Process.inc
diff --git a/lib/Support/Unix/Process.inc b/lib/Support/Unix/Process.inc
index a429bb3984c888a81bafe78031102c08686910ad..eaed72666f9c489ec72270219ba6e9802ad6ec52 100644
--- a/lib/Support/Unix/Process.inc
+++ b/lib/Support/Unix/Process.inc
@@ -265,6 +265,16 @@ std::error_code Process::FixupStandardFileDescriptors() {
 }
 
 std::error_code Process::SafelyCloseFileDescriptor(int FD) {
+  // @LOCALMOD-BEGIN: For NaCl, don't use pthread_sigmask, etc.
+  // They are stubs and fail with ENOSYS, which make this return
+  // an error.
+#ifdef __native_client__
+  int ErrnoFromClose = 0;
+  if (::close(FD) < 0)
+    ErrnoFromClose = errno;
+  return std::error_code(ErrnoFromClose, std::generic_category());
+#else
+
   // Create a signal set filled with *all* signals.
   sigset_t FullSet;
   if (sigfillset(&FullSet) < 0)
@@ -297,6 +307,7 @@ std::error_code Process::SafelyCloseFileDescriptor(int FD) {
   if (ErrnoFromClose)
     return std::error_code(ErrnoFromClose, std::generic_category());
   return std::error_code(EC, std::generic_category());
+#endif  // @LOCALMOD-END
 }
 
 bool Process::StandardInIsUserInput() {