[Issue 1870] Reproduce offending lines in error messages for string mixins

[d-bugmail at puremagic.com]

https://issues.dlang.org/show_bug.cgi?id=1870

--- Comment #4 from github-bugzilla at puremagic.com ---
Commits pushed to master at https://github.com/dlang/dmd

https://github.com/dlang/dmd/commit/3bbb228f3f1239058e4451946554b174dd0a85e1
Fix issues 1870 and 12790: Write out string mixin code to a file for debugging
purpose

https://github.com/dlang/dmd/commit/34db7419c8bbf7487ecd8e7a4eb6adb6fc0bbb74
Merge pull request #8677 from thewilsonator/mixin-debug

Fix issues 1870 and 12790: Write out string mixin code to a file for debugging
purpose

--