Move Struct/ClassDeclaration::toDt into free functions
Move ClassReferenceExp::toDt* into free functions
Merge pull request #3318 from yebblies/classtodt

[DDMD] [refactor] Move remaining toDt methods into free functions
[cleanup] Tweak style of runnable/mangle.d
[cleanup] Gather `mangleof` property related tests into runnable/mangle.d
[cleanup] Adjust test results in runnable/mangle.d
Move *Declaration::toDebug into free functions
Do not put comments between the if body and 'else'
Merge pull request #3320 from 9rnsr/fix_mangle

[cleanup] Gather `mangleof` property related tests into runnable/mangle.d
Merge pull request #3322 from yebblies/todebug

[DDMD] [refactor] Move *Declaration::toDebug into free functions
Merge pull request #3321 from yebblies/bodycomment

[DDMD] Do not put comments between the if body and 'else'
Explicitly cast to unsigned
Clean up comments inside expressions
Merge pull request #3324 from yebblies/64bitcast

[DDMD] Explicitly cast to unsigned
Merge pull request #3325 from yebblies/lastcomments

[DDMD] Fix last remaining comment issues
[cleanup] reduce indentation
Merge pull request #3326 from 9rnsr/refactor_semantic

[cleanup] reduce indentation