Replace use of "0" constraints in inline asm with "+" constraints, when an operand is used both for input and output.
Replace use of "0" constraints in inline asm with "+" constraints,
when an operand is used both for input and output.

Reviewed by:	jhb

jrobhoward/SCADAbase,jrobhoward/SCADAbase,jrobhoward/SCADAbase,jrobhoward/SCADAbase,jrobhoward/SCADAbase,jrobhoward/SCADAbase,jrobhoward/SCADAbase,jrobhoward/SCADAbase,jrobhoward/SCADAbase,jrobhoward/SCADAbase,jrobhoward/SCADAbase