Populate the SourceInfo with Macro replacements

[TristonianJones]

Feature request checklist

• There are no issues that match the desired change
• The change is large enough it can't be addressed with a simple Pull Request
• If this is a bug, please file a Bug Report.

Change
When macro expansions are performed the original source expression is omitted from the ParsedExpr result; however, the original expression is necessary for unparsing the AST back to its original form. Add the macro replacements into the AST.