DIP29-3: function calls
fix Issue 12296 - const compatible AA pointer conversion is wrongly rejected in CTFE
Merge pull request #3355 from 9rnsr/fix12296

[REG2.066a] Issue 12296 - const compatible AA pointer conversion is wrongly rejected in CTFE
fix Issue 12292 - Template specialization ": string" passes for static arrays of other types
Merge pull request #3356 from 9rnsr/fix12292

Issue 12292 - Template specialization ": string" passes for static arrays of other types
Merge pull request #3352 from WalterBright/DIP29-3

DIP29-3: function calls
Issue 5498 - array of elements of subtypes of a common supertype

arrayExpressionsToCommonType incorrectly uses condexp.e2->type rather than condexp.type to determine the common type of the array.