threaded explanation

git-svn-id: http://svn.linuxfromscratch.org/LFS/trunk/BOOK@991 4aa44e1e-78dd-0310-a6d2-fbcd4c07a689

chapter06/gcc-exp.xml

@@ -11,8 +11,9 @@ and C++ compilers and not the other available compilers as they are, on
 the average, not often used. If those other compilers are needed,
 the --enable-languages parameter can be omitted.</para>
 
-<para><userinput>--enable-threads:</userinput> This makes gcc thread
-enabled.</para>
+<para><userinput>--enable-threads:</userinput> C++ exception handling for 
+multithreaded code will not work if gcc is compiled without 
+--enable-threads.</para>
 
 <para><userinput>ln -s ../usr/bin/cpp:</userinput> This
 creates the $LFS/lib/cpp symlink. Some packages explicitly try to find