This patch that sets the EmitAlias flag in td files

and enables the instruction printer to print aliased 
instructions. 

Due to usage of RegisterOperands a change in common 
code (utils/TableGen/AsmWriterEmitter.cpp) is required 
to get the correct register value if it is a RegisterOperand.

Contributer: Vladimir Medic
 


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@174358 91177308-0d34-0410-b5e6-96231b3b80d8