GCC 4.0.0 is a release platform

[SVN r29115]

status/explicit-failures-markup.xml

@@ -35,6 +35,7 @@
     <mark-toolset name="gcc-2.95.3-stlport-4.5.3-linux" status="required"/>
     <mark-toolset name="gcc-3.3.5-linux" status="required"/>
     <mark-toolset name="gcc-3.4.3-linux" status="required"/>
+    <mark-toolset name="gcc-4.0.0-linux" status="required"/>
     <mark-toolset name="gcc-3_3-darwin" status="required"/>
     <mark-toolset name="iw-7_1-vc6" status="required"/>
     <mark-toolset name="iw-7_1-vc6-stlp-4_5_3" status="required"/>