Adjust some test names, remove obsolete and duplicate tests (nikic)

Zend/tests/use_const/conflicting_use_alias.phpt

@@ -1,5 +1,5 @@
 --TEST--
-use and use function with the same alias
+use and use const with the same alias
 --FILE--
 <?php
 

Zend/tests/use_const/function_and_cons.phpt

@@ -1,25 +0,0 @@
---TEST--
-use function and use const in the same block
---FILE--
-<?php
-
-namespace foo {
-    const bar = 'local const';
-    function bar() {
-        return 'local function';
-    }
-}
-
-namespace {
-    use const foo\bar;
-    use function foo\bar;
-    var_dump(bar);
-    var_dump(bar());
-    echo "Done\n";
-}
-
-?>
---EXPECT--
-string(11) "local const"
-string(14) "local function"
-Done

Zend/tests/use_const/shadow_core_null.phpt

@@ -1,12 +0,0 @@
---TEST--
-shadowing null with a local version
---FILE--
-<?php
-
-namespace foo {
-    const null = 42;
-}
-
-?>
---EXPECTF--
-Fatal error: Cannot redeclare constant 'null' in %s on line %d

Zend/tests/use_function/conflicting_use_const_alias.phpt

@@ -1,5 +1,5 @@
 --TEST--
-use and use function with the same alias
+use const and use function with the same alias
 --FILE--
 <?php