ambiguous overload of function call operator allowed

[llvmbot]

Bugzilla Link	30594
Version	trunk
OS	All
Reporter	LLVM Bugzilla Contributor
CC	@DougGregor

Extended Description

The following should be considered ambiguous:

//no error - incorrect behavior
struct B1{void operator()(){}};
struct B2{void operator()(int){}};
struct D:B1,B2{};
int main()
{
D{}();
}

without an explicit using declaration in D the overloads provided by the two bases should be considered ambiguous as in the analogous case for member functions.

//error: member 'f' found in multiple base classes of different types - correct
//behavior
struct B1{void f(){}};
struct B2{void f(int){}};
struct D:B1,B2{};

int main()
{
D{}.f();
}

[wheatman]

duplicate of #22413

[llvmbot]

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