Remove Tempdir package from Ada compiler
The `Tempdir` package has been removed from the Ada compiler, as its functionality is now provided by `System.OS_Lib`.
The Tempdir package in the Ada compiler is no longer needed because its functionality has been replaced by an equivalent routine in System.OS_Lib. System.OS_Lib provides a routine that does not rely on Name_Id, which is an internal compiler data type. The Tempdir package is no longer used by gnatmake.
In Details
This commit removes tempdir.ads and tempdir.adb. The dependency on Tempdir has also been removed from GNATMAKE_OBJS in gcc-interface/Makefile.in. The functionality is now provided by System.OS_Lib, avoiding reliance on the internal Name_Id type.
For Context
The Tempdir package likely provided functionality for creating temporary directories. This commit removes it because the Ada runtime library (System.OS_Lib) now provides a similar function that's more general and doesn't depend on internal compiler details. This simplifies the compiler's code base and reduces dependencies.