gc.realloc: If old block attributes are preserved, communicate them from reallocNoSync to realloc.
remove thread.di header

- Use extern(D) bindings for the core.thread<->rt.tlsgc
  interface to avoid importing a rt module in core.
fix Issue 13034 - [Reg] core.stdc.stdio - deprecation warning with dmd -inline
Merge pull request #866 from WalterBright/fix13034

fix Issue 13034 - [Reg] core.stdc.stdio - deprecation warning with ...
Merge pull request #844 from Safety0ff/reallocbits

gc.realloc: Improve case where old block attributes are preserved
Merge pull request #865 from MartinNowak/tlsgc_externD

remove thread.di header
Mark threadasm.S as not requiring an executable stack.
Merge pull request #868 from klickverbot/threadasm-exec-stack

Mark threadasm.S as not requiring an executable stack.