Test fixes from rollup

Closes rust-lang#14210 (Make Vec.truncate() resilient against failure in Drop)
Closes rust-lang#14206 (Register new snapshots)
Closes rust-lang#14205 (use sched_yield on linux and freebsd)
Closes rust-lang#14204 (Add a crate for missing stubs from libcore)
Closes rust-lang#14201 (Render not_found with an absolute path to the rust stylesheet)
Closes rust-lang#14198 (update valgrind headers)
Closes rust-lang#14174 (Optimize common path of Once::doit)
Closes rust-lang#14162 (Print 'rustc' and 'rustdoc' as the command name for --version)
Closes rust-lang#14145 (Better strict version hash (SVH) computation)

Author: alexcrichton

src/librlibc/lib.rs

@@ -45,16 +45,17 @@ extern "rust-intrinsic" {
 }
 
 #[no_mangle]
-pub unsafe extern "C" fn memcpy(dest: *mut u8, src: *u8, n: uint) {
+pub unsafe extern "C" fn memcpy(dest: *mut u8, src: *u8, n: uint) -> *mut u8 {
     let mut i = 0;
     while i < n {
         *(offset(dest as *u8, i as int) as *mut u8) = *offset(src, i as int);
         i += 1;
     }
+    return dest;
 }
 
 #[no_mangle]
-pub unsafe extern "C" fn memmove(dest: *mut u8, src: *u8, n: uint) {
+pub unsafe extern "C" fn memmove(dest: *mut u8, src: *u8, n: uint) -> *mut u8 {
     if src < dest as *u8 { // copy from end
         let mut i = n;
         while i != 0 {
@@ -68,15 +69,17 @@ pub unsafe extern "C" fn memmove(dest: *mut u8, src: *u8, n: uint) {
             i += 1;
         }
     }
+    return dest;
 }
 
 #[no_mangle]
-pub unsafe extern "C" fn memset(s: *mut u8, c: i32, n: uint) {
+pub unsafe extern "C" fn memset(s: *mut u8, c: i32, n: uint) -> *mut u8 {
     let mut i = 0;
     while i < n {
         *(offset(s as *u8, i as int) as *mut u8) = c as u8;
         i += 1;
     }
+    return s;
 }
 
 #[no_mangle]

src/librustc/back/svh.rs

@@ -352,11 +352,11 @@ mod svh_visitor {
         }
 
         fn visit_struct_def(&mut self, s: &StructDef, ident: Ident,
-                            g: &Generics, n: NodeId, e: E) {
+                            g: &Generics, _n: NodeId, e: E) {
             SawStructDef(content(ident)).hash(self.st);
             // For some reason walk_struct_def does not call walk_generics.
             visit::walk_generics(self, g, e.clone());
-            visit::walk_struct_def(self, s, ident, g, n, e)
+            visit::walk_struct_def(self, s, e)
         }
 
         fn visit_variant(&mut self, v: &Variant, g: &Generics, e: E) {
@@ -461,8 +461,9 @@ mod svh_visitor {
             SawGenerics.hash(self.st); visit::walk_generics(self, g, e)
         }
 
-        fn visit_fn(&mut self, fk: &FnKind, fd: &FnDecl, b: &Block, s: Span, n: NodeId, e: E) {
-            SawFn.hash(self.st); visit::walk_fn(self, fk, fd, b, s, n, e)
+        fn visit_fn(&mut self, fk: &FnKind, fd: &FnDecl, b: &Block, s: Span,
+                    _n: NodeId, e: E) {
+            SawFn.hash(self.st); visit::walk_fn(self, fk, fd, b, s, e)
         }
 
         fn visit_ty_method(&mut self, t: &TypeMethod, e: E) {