clang-format: Fixed missing space between Obj-C for/in and a typecast.

Fixes this bug: https://llvm.org/bugs/show_bug.cgi?id=24504

TokenAnnotator::spaceRequiredBetween was handling TT_ForEachMacro but
not TT_ObjCForIn, so lines that look like:

  for (id nextObject in (NSArray *)myArray)

would incorrectly turn into:

  for (id nextObject in(NSArray *)myArray)

Patch by Kent Sutherland, thank you.

llvm-svn: 249553