i#1551 port to ARM: fix decodelib build error from mcontext changes
i#1551 port to ARM: fix decodelib build error from mcontext changes

SVN-Revision: 2885

bl4ckic3/dynamorio,sigma-random/dynamorio,code4bones/dynamorio,daksunt/dynamorio,AmesianX/dynamorio,code4bones/dynamorio,AmesianX/dynamorio,code4bones/dynamorio,AmesianX/dynamorio,daksunt/dynamorio,sigma-random/dynamorio,sigma-random/dynamorio,daksunt/dynamorio,daksunt/dynamorio,daksunt/dynamorio,code4bones/dynamorio,bl4ckic3/dynamorio,bl4ckic3/dynamorio,bl4ckic3/dynamorio,AmesianX/dynamorio,sigma-random/dynamorio,AmesianX/dynamorio,sigma-random/dynamorio,bl4ckic3/dynamorio,code4bones/dynamorio