[Docs] Update MemorySSA doc to address more feedback.

Primarily, this clarifies wording in a few places, and adds "\ "s to
make the formatting of things like "``Foo`` s" better.

Thanks to Michael Kuperstein for the comments.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@279007 91177308-0d34-0410-b5e6-96231b3b80d8
1 file changed