Use some heuristics so that when a fixit removes a source range, we try

to also remove a trailing space if possible.

For example, removing '__bridge' from:

i = (__bridge I*)p;

should result in:

i = (I*)p;

not:

i = ( I*)p;

rdar://11314821

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@170764 91177308-0d34-0410-b5e6-96231b3b80d8