segredomap: groupPerSegment improvement + addKernelInputStms
segredomap: groupPerSegment improvement + addKernelInputStms

The division between statements that are run before the kernel, and the
statements that are run by each thread in the kernel is now more clear.

added addKernelInputStms function, so hlint will be happy

ihc/futhark,diku-dk/futhark,diku-dk/futhark,diku-dk/futhark,HIPERFIT/futhark,HIPERFIT/futhark,ihc/futhark,HIPERFIT/futhark,diku-dk/futhark,ihc/futhark,diku-dk/futhark