remove gcc 3.x requirement from documentation

This text is no longer accurate. After the patch is applied, the
generated version at http://www.nongnu.org/qemu/qemu-doc.html should be
regenerated.

This patch is also a candidate for the stable branch. (The URL above is
probably generated from the stable branch anyways, so maybe it goes
without saying.)
Signed-off-by: NHollis Blanchard <hollisb@us.ibm.com>

qemu-doc.texi

@@ -2619,16 +2619,6 @@ make install
 @end example
 to install QEMU in @file{/usr/local}.
 
-@subsection GCC version
-
-In order to compile QEMU successfully, it is very important that you
-have the right tools. The most important one is gcc. On most hosts and
-in particular on x86 ones, @emph{gcc 4.x is not supported}. If your
-Linux distribution includes a gcc 4.x compiler, you can usually
-install an older version (it is invoked by @code{gcc32} or
-@code{gcc34}). The QEMU configure script automatically probes for
-these older versions so that usually you don't have to do anything.
-
 @node Windows
 @section Windows