Remove reflectedFields macro

[nicolasstucki]

This macro is problematic because the community buid can be compiled on the non-bootstrapped library.

Fixes #11076

[liufengyun]

This macro is problematic because the community build can be compiled on the non-bootstrapped library.

What is the problem with the non-bootstrapped library? Won't macros still work in that context?

[nicolasstucki]

Macros may not work properly if we change something from one version to the other. Also, if we change the TASTy version number we might be executing code that expects a different version. I hit one of those issues in #11074 which made it impossible to compile the community-build project.

[liufengyun]

Macros may not work properly if we change something from one version to the other. Also, if we change the TASTy version number we might be executing code that expects a different version. I hit one of those issues in #11074 which made it impossible to compile the community-build project.

Thanks for the detailed explanation. So the rule to follow is: don't use macros in any sub-projects of Dotty, due to bootstrapping problems.

[nicolasstucki]

Don't use macros on sub-projects that use the non-bootstrapped compiler. Some projects only compile with the bootstrapped compiler and in those it is fine.