Don't crash when calling ShConstructCompiler with a wrong output

src/compiler/translator/CodeGen.cpp

@@ -40,11 +40,11 @@ TCompiler* ConstructCompiler(
 #else
         // This compiler is not supported in this
         // configuration. Return NULL per the ShConstructCompiler API.
-        return NULL;
+        return nullptr;
 #endif // ANGLE_ENABLE_HLSL
       default:
         // Unknown format. Return NULL per the ShConstructCompiler API.
-        return NULL;
+        return nullptr;
     }
 }
 

src/compiler/translator/ShaderLang.cpp

@@ -189,9 +189,16 @@ ShHandle ShConstructCompiler(sh::GLenum type, ShShaderSpec spec,
                              const ShBuiltInResources* resources)
 {
     TShHandleBase* base = static_cast<TShHandleBase*>(ConstructCompiler(type, spec, output));
+    if (base == nullptr)
+    {
+        return 0;
+    }
+
     TCompiler* compiler = base->getAsCompiler();
-    if (compiler == 0)
+    if (compiler == nullptr)
+    {
         return 0;
+    }
 
     // Generate built-in symbol table.
     if (!compiler->Init(*resources)) {