fix Issue 13498 - Return type is not checked in function template
[Refactoring] Unify parsing code for linkage, uda, and template parameters
fix Issue 13502 - Stray '(' warning not emitted for documentation of enum templates
Merge pull request #4004 from 9rnsr/fix13498

[REG2.067a] Issue 13498 - Return type is not checked in function template
fix Issue 13497 - [ICE e2ir 1911] Array op compiler error
Merge pull request #4007 from 9rnsr/fix13497

[REG2.065] Issue 13497 - [ICE e2ir 1911] Array op compiler error
Merge pull request #4005 from 9rnsr/fix13502

[REG2.065] Issue 13502 - Stray '(' warning not emitted for documentation of enum templates