Allow opening a named pipe on MacOS and Linux.

runtime/bin/file_linux.cc

Index: runtime/bin/file_linux.cc
diff --git a/runtime/bin/file_linux.cc b/runtime/bin/file_linux.cc
index 309971531c94050179c43745ca745f0f6d541a4b..28d10682719f466e75d2ddc09e0095e6074bf462 100644
--- a/runtime/bin/file_linux.cc
+++ b/runtime/bin/file_linux.cc
@@ -156,7 +156,7 @@ File* File::ScopedOpen(const char* name, FileOpenMode mode) {
   struct stat64 st;
   if (TEMP_FAILURE_RETRY(stat64(name, &st)) == 0) {
     // Only accept regular files and character devices.

[rmacnak, 2016/04/15 17:17:29]

regular files, character devices and pipes

[zra, 2016/04/15 18:19:14]

Done.

-    if (!S_ISREG(st.st_mode) && !S_ISCHR(st.st_mode)) {
+    if (!S_ISREG(st.st_mode) && !S_ISCHR(st.st_mode) && !S_ISFIFO(st.st_mode)) {
       errno = (S_ISDIR(st.st_mode)) ? EISDIR : ENOENT;
       return NULL;
     }