Fix mkstemp stuff to be valid D.
Merge pull request #2794 from 9rnsr/fix11533

Issue 11533 - Compiler should allow to being nested for static local template functions
Merge pull request #2805 from yebblies/mkstemp

[DDMD] Fix mkstemp stuff to be valid D.
[Refactoring] Allow calling `Expression::toLvalue` with `sc == NULL`, except `BinAssignExp` and `TemplateExp`.
fix Issue 11322 - ICE with -inline cgcs.c 221