Revert removal of compare nesting

Since we want the user to be able to pass a negative comparison function, the extra layer of wrapping is now needed

src/core/matchers/toThrow.js

@@ -1,42 +1,44 @@
 getJasmineRequireObj().toThrow = function(j$) {
 
   function toThrow(util) {
-    return function(actual, expected) {
-      var result = { pass: false },
-      threw = false,
-      thrown;
+    return {
+      compare: function(actual, expected) {
+        var result = { pass: false },
+          threw = false,
+          thrown;
 
-      if (typeof actual != "function") {
-        throw new Error("Actual is not a Function");
-      }
+        if (typeof actual != "function") {
+          throw new Error("Actual is not a Function");
+        }
 
-      try {
-        actual();
-      } catch (e) {
-        threw = true;
-        thrown = e;
-      }
+        try {
+          actual();
+        } catch (e) {
+          threw = true;
+          thrown = e;
+        }
 
-      if (!threw) {
-        result.message = "Expected function to throw an exception.";
-        return result;
-      }
+        if (!threw) {
+          result.message = "Expected function to throw an exception.";
+          return result;
+        }
 
-      if (arguments.length == 1) {
-        result.pass = true;
-        result.message = "Expected function not to throw, but it threw " + j$.pp(thrown) + ".";
+        if (arguments.length == 1) {
+          result.pass = true;
+          result.message = "Expected function not to throw, but it threw " + j$.pp(thrown) + ".";
+
+          return result;
+        }
+
+        if (util.equals(thrown, expected)) {
+          result.pass = true;
+          result.message = "Expected function not to throw " + j$.pp(expected) + ".";
+        } else {
+          result.message = "Expected function to throw " + j$.pp(expected) + ", but it threw " +  j$.pp(thrown) + ".";
+        }
 
         return result;
       }
-
-      if (util.equals(thrown, expected)) {
-        result.pass = true;
-        result.message = "Expected function not to throw " + j$.pp(expected) + ".";
-      } else {
-        result.message = "Expected function to throw " + j$.pp(expected) + ", but it threw " +  j$.pp(thrown) + ".";
-      }
-
-      return result;
     };
   }