Added remark on compiler flags.

a1_faq-devel.tex

@@ -10,6 +10,13 @@ of ExaHyPE's authors or third party library authors.
 \section{Frequently asked developer questions}\label{sec:dev-faq}
 
 \begin{description}
+ \item [ My code does not compile as \_mm\_\ldots is not found. ]
+    \exahype\ uses aggressive memory prefetching to avoid latency penalties
+    when it accesses the main memory through the caches. These techniques
+    work on Intel systems as long as the system has the required libraries
+    installed. If you run into problems, please add the parameter
+    \texttt{-DnoTBBPrefetchesJobData} to your compile flags.
+%
  \item [ How do I link my own libraries against \exahype? ]
     \exahype\ uses the two environment variables \texttt{COMPILER\_CFLAGS}
     and \texttt{COMPILER\_LFLAGS} to build up all settings for the actual