Improve tests on 32bit

The watch_*.phpt test apparently no longer fail on 32bit, so we remove
the XFAIL conditions.  bug77269.phpt is practically identical to
bug77272.phpt, and there seems no particular reason to have an
additional test for libgd ≤ 2.2.5.

Closes GH-8448.

Author: mvorisek

ext/gd/tests/bug77269.phpt

@@ -2,9 +2,6 @@
 Test simple recursive watchpoint
 --SKIPIF--
 <?php
-if (PHP_INT_SIZE == 4) {
-    die("xfail There may be flaws in the implementation of watchpoints that cause failures");
-}
 if (getenv('SKIP_ASAN')) {
     die("skip intentionally causes segfaults");
 }

sapi/phpdbg/tests/watch_001.phpt

@@ -2,9 +2,6 @@
 Test simple array watchpoint with replace
 --SKIPIF--
 <?php
-if (PHP_INT_SIZE == 4) {
-    die("xfail There may be flaws in the implementation of watchpoints that cause failures");
-}
 if (getenv('SKIP_ASAN')) {
     die("skip intentionally causes segfaults");
 }

sapi/phpdbg/tests/watch_002.phpt

@@ -2,9 +2,6 @@
 Test simple watchpoint with replace
 --SKIPIF--
 <?php
-if (PHP_INT_SIZE == 4) {
-    die("xfail There may be flaws in the implementation of watchpoints that cause failures");
-}
 if (getenv('SKIP_ASAN')) {
     die("skip intentionally causes segfaults");
 }

sapi/phpdbg/tests/watch_003.phpt

@@ -2,9 +2,6 @@
 Test detection of inline string manipulations on zval watch
 --SKIPIF--
 <?php
-if (PHP_INT_SIZE == 4) {
-    die("xfail There may be flaws in the implementation of watchpoints that cause failures");
-}
 if (getenv('SKIP_ASAN')) {
     die("skip intentionally causes segfaults");
 }