Fix inconsistency in true/false/null constant resolution when eval() is used

Strangely, uses of eval and 'php -a' will not treat non-FQ true/false/null as magic
keywords, while compiled php required from a file would do that.

This may confuse people learning the language, and result in code loaded with
eval() behaving differently from the same snippet in a file loaded by require.

```
Interactive shell

php > define('foo\true', 'test');
php > namespace foo { var_dump(true); }
string(4) "test"
```

This will make the same session instead properly emit `bool(true);` like it
already would if running those statements in files.
(Interactive shell internally uses the same APIs eval uses)

`zend_resolve_non_class_name` is a static C function where case_sensitive
is only true for global constants (and false for global functions).

Author: TysonAndre

Zend/tests/eval_constant_resolution.phpt

@@ -0,0 +1,23 @@
+--TEST--
+eval() constant resolution
+--FILE--
+<?php
+namespace foo {
+define('foo\true', 'test');
+echo "In eval\n";
+eval('namespace foo { var_dump(true); var_dump(TrUe); var_dump(namespace\true); var_dump(\true); }');
+echo "Outside eval\n";
+var_dump(true); var_dump(TrUe); var_dump(namespace\true); var_dump(\true);
+}
+?>
+--EXPECT--
+In eval
+bool(true)
+bool(true)
+string(4) "test"
+bool(true)
+Outside eval
+bool(true)
+bool(true)
+string(4) "test"
+bool(true)

Zend/zend_compile.c

@@ -1475,28 +1475,26 @@ static bool can_ct_eval_const(zend_constant *c) {
 
 static bool zend_try_ct_eval_const(zval *zv, zend_string *name, bool is_fully_qualified) /* {{{ */
 {
-	zend_constant *c = zend_hash_find_ptr(EG(zend_constants), name);
+	/* Substitute true, false and null (including unqualified usage in namespaces)
+	 * before looking up the possibly namespaced name. */
+	const char *lookup_name = ZSTR_VAL(name);
+	size_t lookup_len = ZSTR_LEN(name);
+
+	if (!is_fully_qualified) {
+		zend_get_unqualified_name(name, &lookup_name, &lookup_len);
+	}
+
+	zend_constant *c;
+	if ((c = zend_get_special_const(lookup_name, lookup_len))) {
+		ZVAL_COPY_VALUE(zv, &c->value);
+		return 1;
+	}
+	c = zend_hash_find_ptr(EG(zend_constants), name);
 	if (c && can_ct_eval_const(c)) {
 		ZVAL_COPY_OR_DUP(zv, &c->value);
 		return 1;
 	}
-
-	{
-		/* Substitute true, false and null (including unqualified usage in namespaces) */
-		const char *lookup_name = ZSTR_VAL(name);
-		size_t lookup_len = ZSTR_LEN(name);
-
-		if (!is_fully_qualified) {
-			zend_get_unqualified_name(name, &lookup_name, &lookup_len);
-		}
-
-		if ((c = zend_get_special_const(lookup_name, lookup_len))) {
-			ZVAL_COPY_VALUE(zv, &c->value);
-			return 1;
-		}
-
-		return 0;
-	}
+	return 0;
 }
 /* }}} */