boost: disable spurious MSVC warning C4100 in msvc.hpp

It warns that "x" is unreferenced formal parameter in
virtual void failed(Model *x) { x->~Model(); }

Change-Id: I10a4e1f037726f0225c2c6bf4ee23d5fb2accf7d

boost/UnpackedTarball_boost.mk

@@ -26,6 +26,7 @@ boost_patches += boost.6397.warnings.patch
 boost_patches += boost.mipsbackport.patch
 #https://svn.boost.org/trac/boost/ticket/7551
 boost_patches += boost.7551.unusedvars.patch
+boost_patches += boost.4100.warnings.patch
 
 boost_patches += boost.windows.patch
 boost_patches += boost.vc2012.patch

boost/boost.4100.warnings.patch

+--- misc/boost_1_44_0/boost/concept/detail/msvc.hpp
++++ misc/build/boost_1_44_0/boost/concept/detail/msvc.hpp
+@@ -12,6 +12,9 @@
+ #  include <boost/mpl/if.hpp>
+ # endif
+ 
++// disable spurious "unreferenced formal parameter" warnings
++#pragma warning( push )
++#pragma warning( disable: 4100 )
+ 
+ namespace boost { namespace concepts {
+ 
+@@ -111,4 +114,6 @@
+ # endif
+ }}
+ 
++#pragma warning( pop )
++
+ #endif // BOOST_CONCEPT_CHECK_MSVC_DWA2006429_HPP