Replace runTestCase with assert helpers [test/built-ins/Error]

test/built-ins/Error/prototype/toString/15.11.4.4-10-1.js

@@ -7,12 +7,9 @@ description: >
     Error.prototype.toString return the result of concatenating
     'name', ':', a single space character, and 'msg' when 'name' and
     'msg' are non-empty string
-includes: [runTestCase.js]
 ---*/
 
-function testcase() {
         var errObj = new Error("ErrorMessage");
         errObj.name = "ErrorName";
-        return errObj.toString() === "ErrorName: ErrorMessage";
-    }
-runTestCase(testcase);
+
+assert.sameValue(errObj.toString(), "ErrorName: ErrorMessage", 'errObj.toString()');

test/built-ins/Error/prototype/toString/15.11.4.4-6-1.js

@@ -6,11 +6,8 @@ es5id: 15.11.4.4-6-1
 description: >
     Error.prototype.toString - 'Error' is returned when 'name' is
     absent and empty string is returned when 'msg' is undefined
-includes: [runTestCase.js]
 ---*/
 
-function testcase() {
         var errObj = new Error();
-        return errObj.toString() === "Error";
-    }
-runTestCase(testcase);
+
+assert.sameValue(errObj.toString(), "Error", 'errObj.toString()');

test/built-ins/Error/prototype/toString/15.11.4.4-6-2.js

@@ -7,11 +7,8 @@ description: >
     Error.prototype.toString - 'Error' is returned when 'name' is
     absent and value of 'msg' is returned when 'msg' is non-empty
     string
-includes: [runTestCase.js]
 ---*/
 
-function testcase() {
         var errObj = new Error("ErrorMessage");
-        return errObj.toString() === "Error: ErrorMessage";
-    }
-runTestCase(testcase);
+
+assert.sameValue(errObj.toString(), "Error: ErrorMessage", 'errObj.toString()');

test/built-ins/Error/prototype/toString/15.11.4.4-8-1.js

@@ -6,12 +6,9 @@ es5id: 15.11.4.4-8-1
 description: >
     Error.prototype.toString return the value of 'msg' when 'name' is
     empty string and 'msg' isn't undefined
-includes: [runTestCase.js]
 ---*/
 
-function testcase() {
         var errObj = new Error("ErrorMessage");
         errObj.name = "";
-        return errObj.toString() === "ErrorMessage";
-    }
-runTestCase(testcase);
+
+assert.sameValue(errObj.toString(), "ErrorMessage", 'errObj.toString()');

test/built-ins/Error/prototype/toString/15.11.4.4-9-1.js

@@ -6,12 +6,9 @@ es5id: 15.11.4.4-9-1
 description: >
     Error.prototype.toString return 'name' when 'name' is non-empty
     string and 'msg' is empty string
-includes: [runTestCase.js]
 ---*/
 
-function testcase() {
         var errObj = new Error();
         errObj.name = "ErrorName";
-        return errObj.toString() === "ErrorName";
-    }
-runTestCase(testcase);
+
+assert.sameValue(errObj.toString(), "ErrorName", 'errObj.toString()');