DIP1034 add noreturn to object, abort, exit, _Exit

Author: WalterBright

src/core/stdc/stdlib.d

@@ -164,13 +164,13 @@ void*   realloc(void* ptr, size_t size);
 void    free(void* ptr);
 
 ///
-void    abort() @safe;
+noreturn abort() @safe;
 ///
-void    exit(int status);
+noreturn exit(int status);
 ///
 int     atexit(void function() func);
 ///
-void    _Exit(int status);
+noreturn _Exit(int status);
 
 ///
 char*   getenv(scope const char* name);

src/object.d

@@ -15,6 +15,7 @@ alias size_t = typeof(int.sizeof);
 alias ptrdiff_t = typeof(cast(void*)0 - cast(void*)0);
 
 alias sizediff_t = ptrdiff_t; // For backwards compatibility only.
+alias noreturn = typeof(*null);  /// bottom type
 
 alias hash_t = size_t; // For backwards compatibility only.
 alias equals_t = bool; // For backwards compatibility only.