Added support for sendmsg(MSG[, OP[, STREAM_ID]]) syntax
in s_sendmsg and s_sendmsghalt instructions.
The syntax matches the SP3 assembler/disassembler rules.
That is why implicit inputs (like M0 and EXEC) are not printed
to disassembly output anymore.
sendmsg(...) allows only known message types and attributes,
even if literals are used instead of symbolic names.
However, raw literal (without "sendmsg") still can be used,
and that allows for any 16-bit value.
Tests updated/added.
Differential Revision: http://reviews.llvm.org/D19596
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@268762 91177308-0d34-0410-b5e6-96231b3b80d8
