Make x86_64 zdot compile with PGI and Sun C again
Make x86_64 zdot compile with PGI and Sun C again

broken by #2222 as CREAL,CIMAG do not expand to a valid lvalue with these compilers
xianyi/OpenBLAS,xianyi/OpenBLAS,xianyi/OpenBLAS,xianyi/OpenBLAS,xianyi/OpenBLAS,xianyi/OpenBLAS,xianyi/OpenBLAS,xianyi/OpenBLAS