Merge pull request #2811 from yebblies/builtin

[Unified Frontend] Implement a callback-based builtin hook using mangled names
Fix Issue 11802 - Wrong vtbl order for extern(C++) classes with overloaded functions on win32
Make entrypoint to "root module"
fix Issue 11447 - Closure provide bogus values
fix Issue 11843 - Template instantiated twice: failed semantic analysis
Merge pull request #3049 from 9rnsr/fix11843

Issue 11843 - Template instantiated twice: failed semantic analysis
Merge pull request #3022 from yebblies/issue10199

Issue 10199 - labels cannot be used without a statement
Merge pull request #2467 from 9rnsr/extend_dip42

Extend DIP42 proposal to more generic
Merge pull request #3050 from 9rnsr/fix11447

fix Issue 11447 - Closure provide bogus values
Merge pull request #3020 from 9rnsr/faildiag

Issue 11813 & 11814 - improve diagnostic messages on IFTI failure
Fix Issue 11559 - Optlink crash with more than 2048 modules generated and debug info
Merge pull request #3051 from yebblies/issue11559

Fix Issue 11559 - Optlink crash with more than 2048 modules generated and debug info
Merge pull request #3010 from yebblies/issue11802

[DDMD] Issue 11802 - Wrong vtbl order for extern(C++) classes with overloaded functions on win32
Always create libs through named factory functions
Add factory function for TypeTuple
Use factory functions instead of calling constructors from the glue layer
Use factory functions to create arrays from the glue layer
Merge pull request #3005 from yebblies/factory

[DDMD] Use factory functions instead of calling constructors from the glue layer
Merge pull request #3032 from yebblies/libfactory

[DDMD] Always create libs through named factory functions
Merge pull request #2990 from denis-sh/workaround-regression-11777

Workaround regression 11777.