DI Generation Improvements.
Improper permute argument in header.d.
Set +x on the postscripts.
Merge pull request #1492 from yebblies/issue9195

Fix Issue 9195 - Should not be able to index a pointer in safed
Merge pull request #1487 from LightBender/digen2

DI Generation Improvements.
Fix Issue 6169 - [CTFE] pure functions cannot compute constants using functions not marked as pure

When running semantic on an expression used anywhere that forces compile time evaluation, use a scope flag to prevent purity and safety checks on function calls.
This allows better purity/safety inferrence as well.
Restore case variables