Check that matched symbol is always a FuncDeclaration
Merge pull request #2016 from yebblies/checkassumption

[DDMD] Check that matched symbol is always a FuncDeclaration
fix Issue 10063 - inout+pure results in ability to produce immutable reference to mutable data
Merge pull request #2031 from 9rnsr/fix10063

Issue 10063 - inout+pure results in ability to produce immutable reference to mutable data