[Fix #1255] Compare without context in AutocorrectUnlessChangingAST

For example, if the operands of and/or are local variables, the
syntax tree for the new source code (that has no context) would
be different from the original, but not in a meaningful way. The
correction might still be valid.
Merge pull request #1260 from jonas054/1255_fix_and_or_autocorrect

[Fix #1255] Compare without context in AutocorrectUnlessChangingAST