GCC4: enable C++11 threads support.

* This is required for building WebKit.

sys-devel/gcc/gcc-4.8.2_2014_01_28.recipe

@@ -12,7 +12,7 @@ SRC_URI="
 	git+file://$portBaseDir/../binutils/download/buildtools.git#66becd8fe7e99054b190c181b063933310718179
 	git+git://github.com/haiku/buildtools.git#66becd8fe7e99054b190c181b063933310718179
 	"
-REVISION="1"
+REVISION="2"
 ARCHITECTURES="x86 x86_64"
 if [ $effectiveTargetArchitecture != x86_gcc2 ]; then
 	# x86_gcc2 is fine as primary target architecture as long as we're building
@@ -85,7 +85,7 @@ BUILD()
 	CFLAGS="-O2 -U_FORTIFY_SOURCE" CXXFLAGS="-O2" "$sourceDir/configure" \
 		--build=$effectiveTargetMachineTriple \
 		--prefix=$installDir --libexecdir=$installDir/lib --mandir=$manDir \
-		--docdir=$docDir \
+		--docdir=$docDir --enable-threads=posix \
 		--disable-nls --enable-shared --with-gnu-ld \
 		--enable-languages=c,c++ --enable-lto --enable-frame-pointer \
 		--with-pkgversion=$(echo $portVersion | cut -c 7-) \