osint.adb: Add use type clause for CRTL.size_t.

osint.adb: Add use type clause for CRTL.size_t.

	* osint.adb: Add use type clause for CRTL.size_t.
	(C_String_Length): Return CRTL.size_t instead of Integer.
	(To_Path_String_Access): Take CRTL.size_t instead of Integer.
	(Get_Libraries_From_Registry): Use CRTL throughout.
	(To_Canonical_Dir_Spec): Use CRTL.size_t instead of Integer.
	(To_Canonical_File_List): Likewise.
	(To_Canonical_File_Spec): Likewise.
	(To_Canonical_Path_Spec): Likewise.
	(To_Host_Dir_Spec): Likewise.
	(To_Host_File_Spec): Likewise.
	(Update_Path): Use CRTL throughout.
	* s-shasto.adb: Add with clause for System.CRTL.
	(Initialize): Rename CRTL.strncpy instead of importing it manually.

From-SVN: r231066