QtDeclarative Does not Build on Clang

QtDeclarative no longer builds with Clang in C++11 mode due to a recent change in qv4arrayobject.cpp: the new code is

ReturnedValue ArrayPrototype::method_isArray(SimpleCallContext *ctx)
{
bool isArray = ctx->argumentCount ? ctx->arguments[0].asArrayObject() : false;
return Encode(isArray);
}

Clang reports: jsruntime/qv4arrayobject.cpp:135:39: error: incompatible operand types ('QV4::ArrayObject *' and 'bool')

The Clang developers referred me to the C++11 standard, section 5.16, on the conditional operator. This section describes some technical requirements for the operands of the conditional operator.