test: Fix mismatched types in prep for typechecker fixes

Issue #500

Author: brson

src/test/compile-fail/break-uninit.rs

@@ -8,7 +8,7 @@ fn foo() -> int {
     i = 0;
     break;
     x = 0;
-  } while ((x = 0) != 0);
+  } while (x != 0);
 
   log(x);
 

src/test/run-fail/if-check-fail.rs

@@ -1,14 +1,14 @@
 // xfail-stage0
 // error-pattern:Number is odd
 pred even(uint x) -> bool {
-  if (x < 2) {
+  if (x < 2u) {
     ret false;
   }
-  else if (x == 2) {
+  else if (x == 2u) {
     ret true;
   }
   else {
-    ret even(x - 2);
+    ret even(x - 2u);
   }
 }
 

src/test/run-pass/if-check.rs

@@ -1,14 +1,14 @@
 // xfail-stage0
 
 pred even(uint x) -> bool {
-  if (x < 2) {
+  if (x < 2u) {
     ret false;
   }
-  else if (x == 2) {
+  else if (x == 2u) {
     ret true;
   }
   else {
-    ret even(x - 2);
+    ret even(x - 2u);
   }
 }