MC: collapse emission of producer

Rather than use three EmitBytes, concatenate the string at compile time,
constructing a single StringRef and emitting the data in one shot.  This also
creates nicer assembly output.  NFC.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@213273 91177308-0d34-0410-b5e6-96231b3b80d8
1 file changed