fix Issue 12242 - conflict error with public imports
[Refactoring] Add ScopeDsymbol::mergeOverloadSet
fix Issue 13221 - [ICE] '0' on line 318 in file 'interpret.c'
Merge pull request #3824 from 9rnsr/fix13221

[REG2.064] Issue 13221 - [ICE] '0' on line 318 in file 'interpret.c'
Merge pull request #3388 from 9rnsr/fix12242

Issue 12242 - conflict error with public imports
fix Issue 13220 - [ICE] 'global.gaggedErrors || global.errors' on line 750 in file 'statement.c'
Merge pull request #3833 from 9rnsr/fix13220

[REG2.066a] Issue 13220 - [ICE] 'global.gaggedErrors || global.errors' on line 750 in file 'statement.c'
Fix Issue 7942 - Appending different string types corrupts memory