Fix for PR18921, "vmov" part.
Added support for bytes replication feature, so it could be GAS compatible.

E.g. instructions below:
"vmov.i32 d0, 0xffffffff"
"vmvn.i32 d0, 0xabababab"
"vmov.i32 d0, 0xabababab"
"vmov.i16 d0, 0xabab"
are incorrect, but we could deal with such cases.

For first one we should emit:
"vmov.i8 d0, 0xff"
For second one ("vmvn"):
"vmov.i8 d0, 0x54"
For last two instructions it should emit:
"vmov.i8 d0, 0xab"

P.S.: In ARMAsmParser.cpp I have also fixed few nearby style issues in old code.
Just for keeping method bodies in harmony with themselves.