gen_stub: replace AbstractConstName::isClassConst() with instanceof

build/gen_stub.php

@@ -898,8 +898,6 @@ public function getDeclarationName(): string;
 
 abstract class AbstractConstName implements VariableLikeName
 {
-    abstract public function isClassConst(): bool;
-
     public function isUnknown(): bool
     {
         return strtolower($this->__toString()) === "unknown";
@@ -917,11 +915,6 @@ public function __construct(?Name $namespace, string $const)
         $this->const = $const;
     }
 
-    public function isClassConst(): bool
-    {
-        return false;
-    }
-
     public function isUnknown(): bool
     {
         $name = $this->__toString();
@@ -952,11 +945,6 @@ public function __construct(Name $class, string $const)
         $this->const = $const;
     }
 
-    public function isClassConst(): bool
-    {
-        return true;
-    }
-
     public function __toString(): string
     {
         return $this->class->toString() . "::" . $this->const;
@@ -2800,7 +2788,7 @@ public function getDeclaration(array $allConstInfos): string
             $code .= "#if {$this->cond}\n";
         }
 
-        if ($this->name->isClassConst()) {
+        if ($this->name instanceof ClassConstName) {
             $code .= $this->getClassConstDeclaration($value, $allConstInfos);
         } else {
             $code .= $this->getGlobalConstDeclaration($value);
@@ -6276,7 +6264,7 @@ function(?ArgInfo $aliasArg, ?ArgInfo $aliasedArg) use ($aliasFunc, $aliasedFunc
 
 if ($verifyManual) {
     foreach ($undocumentedConstMap as $constName => $info) {
-        if ($info->name->isClassConst() || $info->isUndocumentable) {
+        if ($info->name instanceof ClassConstName || $info->isUndocumentable) {
             continue;
         }