Fix unwanted Real to Scalar to Real conversions in column-pivoting QR.
Fix unwanted Real to Scalar to Real conversions in column-pivoting QR.

ritsu1228/eigen,pasuka/eigen,ritsu1228/eigen,pasuka/eigen,pasuka/eigen,pasuka/eigen,ritsu1228/eigen,ritsu1228/eigen,pasuka/eigen,ritsu1228/eigen