Updated debugging metadata for ty_nil and ty_bot

ty_nil will now report as "()" in gdb
ty_bot will now report as "!" in gdb

Added test to confirm basic types debugging metadata.

This fixes #9226

src/librustc/middle/trans/debuginfo.rs

@@ -1015,7 +1015,8 @@ fn basic_type_metadata(cx: &mut CrateContext, t: ty::t) -> DIType {
     debug!("basic_type_metadata: {:?}", ty::get(t));
 
     let (name, encoding) = match ty::get(t).sty {
-        ty::ty_nil | ty::ty_bot => (~"uint", DW_ATE_unsigned),
+        ty::ty_nil => (~"()", DW_ATE_unsigned),
+        ty::ty_bot => (~"!", DW_ATE_unsigned),
         ty::ty_bool => (~"bool", DW_ATE_boolean),
         ty::ty_char => (~"char", DW_ATE_unsigned_char),
         ty::ty_int(int_ty) => match int_ty {

src/test/debug-info/basic-types-metadata.rs

@@ -0,0 +1,73 @@
+// Copyright 2013 The Rust Project Developers. See the COPYRIGHT
+// file at the top-level directory of this distribution and at
+// http://rust-lang.org/COPYRIGHT.
+//
+// Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or
+// http://www.apache.org/licenses/LICENSE-2.0> or the MIT license
+// <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your
+// option. This file may not be copied, modified, or distributed
+// except according to those terms.
+
+// compile-flags:-Z extra-debug-info
+// debugger:rbreak zzz
+// debugger:run
+// debugger:finish
+// debugger:whatis unit
+// check:type = ()
+// debugger:whatis b
+// check:type = bool
+// debugger:whatis i
+// check:type = int
+// debugger:whatis c
+// check:type = char
+// debugger:whatis i8
+// check:type = i8
+// debugger:whatis i16
+// check:type = i16
+// debugger:whatis i32
+// check:type = i32
+// debugger:whatis i64
+// check:type = i64
+// debugger:whatis u
+// check:type = uint
+// debugger:whatis u8
+// check:type = u8
+// debugger:whatis u16
+// check:type = u16
+// debugger:whatis u32
+// check:type = u32
+// debugger:whatis u64
+// check:type = u64
+// debugger:whatis f32
+// check:type = f32
+// debugger:whatis f64
+// check:type = f64
+// debugger:info functions _yyy
+// check:[...]
+// check:! basic-types-metadata::_yyy()();
+// debugger:detach
+// debugger:quit
+
+#[allow(unused_variable)];
+
+fn main() {
+    let unit: () = ();
+    let b: bool = false;
+    let i: int = -1;
+    let c: char = 'a';
+    let i8: i8 = 68;
+    let i16: i16 = -16;
+    let i32: i32 = -32;
+    let i64: i64 = -64;
+    let u: uint = 1;
+    let u8: u8 = 100;
+    let u16: u16 = 16;
+    let u32: u32 = 32;
+    let u64: u64 = 64;
+    let f32: f32 = 2.5;
+    let f64: f64 = 3.5;
+    _zzz();
+}
+
+fn _zzz() {()}
+fn _yyy() -> ! {fail!()}