mlir

Add a check that FIRRTL's regreset errors if the type of the reset value doesn't match the type of reset. E.g., the following should fail because a vector register is being reset to a ground type. However, it does not fail and will crash LowerTypes:

%r = firrtl.regreset %clock, %reset, %c0_ui1  : (!firrtl.clock, !firrtl.asyncreset, !firrtl.uint<1>) -> !firrtl.vector<uint<1>, 1>
``

@honglh added optimized kernels for ARM32 in #432. It would be great if we could add support for bitpacked activations to them to match the AArch64 optimized bgemm kernels.