Update to the latest Chisel

333bb95 Merge pull request #232 from palmer-dabbelt/flo-log2
855ad54 Remove a spurious newline from Flo's log2 generation rule
7c1e8c3 Merge branch 'palmer-dabbelt-cast'
57df33d Merge branch 'cast' of github.com:palmer-dabbelt/chisel into palmer-dabbelt-cast
6d32dd9 Merge pull request #230 from palmer-dabbelt/long_rsh
15f3035 Fix a code-gen issue related to reinterpret_cast
fdcac4e Fix long RSH by adding dat_t::operator[](size_t)
bcbe3e3 Merge pull request #228 from ccelio/master
81d77b0 Added --vcdMem option for dumping Memory/ROM state.
41aef31 Merge pull request #224 from zhemao/shiftreg-doc