Fix variable shadowing
Explicitly cast array bounds to size_t
Fix implicit conversion to bool
Remove unused and shadowing variable
Merge pull request #3563 from yebblies/boolconvx

[DDMD] Fix implicit conversion to bool
Merge pull request #3560 from yebblies/shadowidents

[DDMD] Remove unused and shadowing variable
Merge pull request #3561 from yebblies/sc2shadow

[DDMD] Fix variable shadowing
Merge pull request #3562 from yebblies/sizetcast

[DDMD] Explicitly cast array bounds to size_t