MFC r350532-350536,350559,350584-350585,350746-350747:
Merge the first part of frag6.c changes from HEAD. Apart from moving the
sysctls into the local file these are mostly non-functional changes.
frag6.c: sort includes frag6.c: move variables and sysctls into local file frag6.c: remove dead code frag6.c: rename malloc type frag6.c: make compile with gcc frag6.c: fix includes frag6.c: re-order functions within file frag6.c: rename ip6q[] to ipq6b[] and consistently use "bucket" frag6.c: initial comment and whitespace cleanup. frag6.c: cleanup varaibles and return statements. Sponsored by: Netflix