In-house patch for firefox to build with GNU compilers. 
With GNU compiler, we have hunspell_fopen_hooks.h included 
through mozilla-config.h.
But we don't have an implementation for mozilla::ReadAheadFile().

diff --git a/xpcom/glue/FileUtils.cpp b/xpcom/glue/FileUtils.cpp
--- a/xpcom/glue/FileUtils.cpp
+++ b/xpcom/glue/FileUtils.cpp
@@ -481,17 +481,17 @@ mozilla::ReadAheadFile(mozilla::pathstr_
   }
   if (fd == INVALID_HANDLE_VALUE) {
     return;
   }
   ReadAhead(fd, aOffset, aCount);
   if (!aOutFd) {
     CloseHandle(fd);
   }
-#elif defined(LINUX) && !defined(ANDROID) || defined(XP_MACOSX)
+#elif defined(LINUX) && !defined(ANDROID) || defined(XP_MACOSX) || defined(SOLARIS)
   if (!aFilePath) {
     if (aOutFd) {
       *aOutFd = -1;
     }
     return;
   }
   int fd = open(aFilePath, O_RDONLY);
   if (aOutFd) {