Delete a comment that makes no sense to me. The statement that moving a CPE

Delete a comment that makes no sense to me.  The statement that moving a CPE
before its reference is only supported on ARM has not been true for a while.
In fact, until recently, that was only supported for Thumb.  Besides that,
CPEs are always a multiple of 4 bytes in size, so inserting a CPE should have
no effect on Thumb alignment.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@83916 91177308-0d34-0410-b5e6-96231b3b80d8