Add tests for extract error conditions

Author: Girgias

ext/standard/tests/array/extract_error_variation1.phpt

@@ -0,0 +1,15 @@
+--TEST--
+Test extract() function - error condition - Invalid flag argument.
+--FILE--
+<?php
+$a = ["1" => "one", "2" => "two", "3" => "three", "4" => "four", "5" => "five"];
+
+try {
+    extract($a, 10000);
+} catch (\Error $e) {
+    echo $e->getMessage();
+}
+
+?>
+--EXPECT--
+Invalid extract type

ext/standard/tests/array/extract_error_variation2.phpt

@@ -0,0 +1,15 @@
+--TEST--
+Test extract() function - error condition - Prefix flag without supplying prefix.
+--FILE--
+<?php
+$a = ["1" => "one", "2" => "two", "3" => "three", "4" => "four", "5" => "five"];
+
+try {
+    extract($a, EXTR_PREFIX_ALL);
+} catch (\Error $e) {
+    echo $e->getMessage();
+}
+
+?>
+--EXPECT--
+Specified extract type requires the prefix parameter

ext/standard/tests/array/extract_error_variation3.phpt

@@ -0,0 +1,14 @@
+--TEST--
+Test extract() function - error condition - Invalid prefix.
+--FILE--
+<?php
+$a = ["1" => "one", "2" => "two", "3" => "three", "4" => "four", "5" => "five"];
+
+try {
+    extract($a, EXTR_PREFIX_ALL, '85bogus');
+} catch (\Error $e) {
+    echo $e->getMessage();
+}
+?>
+--EXPECT--
+Prefix is not a valid identifier