test: Get rid of some @muts in borrow check tests

Author: pcwalton

src/test/compile-fail/borrowck-loan-rcvr-overloaded-op.rs

@@ -49,13 +49,5 @@ fn b() {
     q.x += 1; // and OK to mutate it
 }
 
-fn c() {
-    // Here the receiver is in aliased memory but due to write
-    // barriers we can still consider it immutable.
-    let q = @mut Point {x: 3, y: 4};
-    *q + 3;
-    q.times(3);
-}
-
 fn main() {
 }

src/test/compile-fail/borrowck-loan-rcvr.rs

@@ -48,16 +48,5 @@ fn b() {
     l.x += 1;
 }
 
-fn c() {
-    // Loaning @mut as & is considered legal due to dynamic checks...
-    let q = @mut point {x: 3, y: 4};
-    q.impurem();
-
-    // ...but we still detect errors statically when we can.
-    q.blockm(|| {
-        q.x = 10; //~ ERROR cannot assign
-    })
-}
-
 fn main() {
 }

src/test/compile-fail/borrowck-mut-boxed-vec.rs

@@ -12,7 +12,7 @@
 
 struct foo(~int);
 
-fn borrow(x: @mut foo) {
+fn borrow(x: @foo) {
     let _y = &***x;
     *x = foo(~4); //~ ERROR cannot assign
 }

src/test/compile-fail/borrowck-mut-deref-comp.rs

@@ -30,11 +30,6 @@ fn managed_receiver(x: @Foo) {
     x.borrowed_mut(); //~ ERROR cannot borrow
 }
 
-fn managed_mut_receiver(x: @mut Foo) {
-    x.borrowed();
-    x.borrowed_mut();
-}
-
 fn owned_receiver(x: ~Foo) {
     x.borrowed();
     x.borrowed_mut(); //~ ERROR cannot borrow

src/test/compile-fail/borrowck-object-mutability.rs

@@ -14,6 +14,6 @@ struct F { f: @G }
 struct G { g: ~[int] }
 
 pub fn main() {
-    let rec = @mut F {f: @G {g: ~[1, 2, 3]}};
+    let rec = @F {f: @G {g: ~[1, 2, 3]}};
     while rec.f.g.len() == 23 {}
 }

src/test/run-pass/borrowck-root-while-cond-2.rs

@@ -15,6 +15,6 @@ fn borrow<'r,T>(x: &'r T) -> &'r T {x}
 struct Rec { f: @int }
 
 pub fn main() {
-    let rec = @mut Rec {f: @22};
+    let rec = @Rec {f: @22};
     while *borrow(rec.f) == 23 {}
 }