add PROFILING_OUTDIR support

Signed-off-by: xiehuc <xiehuc@gmail.com>
create OUTDIR if not exist

Signed-off-by: xiehuc <xiehuc@gmail.com>
add ProfileInfoWriter Api

Signed-off-by: xiehuc <xiehuc@gmail.com>
update FindLLVM

Signed-off-by: xiehuc <xiehuc@gmail.com>
Merge branch 'xie'
add the function of merging file,not add write file