neon/movl: add WASM implementations
neon/movl: add WASM implementations

I don't actually think these are necessary since clang and emscripten
support __builtin_convertvector (which is how these are implemented in
clang's wasm_simd128.h), so we should get the same results.  If we ever
get other compilers which target WebAssembly but don't support
__builtin_convertvector (I know, I'm not holding by breath), this will
be great…

nemequ/simde,nemequ/simde,nemequ/simde