ASAN fails to detect alignment mismatched delete calls

[ahh]

class alignas(64) Foo {
char buf[64];
};

class Bar {
char buf[64];
};

Foo *f = new Foo;
Bar *b = new Bar;
volatile Foo *nf = reinterpret_cast<Foo *>(b);
volatile Bar *nb = reinterpret_cast<Bar *>(f);
DoNotOptimize(nf); // prevent new/delete elision somehow
DoNotOptimize(nb);
delete nf;
delete nb;

This does not error out. At least as of C++17, I believe it should be able to make it do so (and that it is important to in fact do so)--becuase the "delete nf" call should invoke a aligned delete operator (3 or 7 here http://en.cppreference.com/w/cpp/memory/new/operator_delete) and the delete nb call should not.

[kcc]

we will need to intercept operator new/delete with the alignment argument and then store
the alignment in asan's ChunkHeader.
3 bits should be enough to represent 8 different alignment values: none, 8, 16, 32, 64, 128, 256, 512+.
We can steal 3 bits from u32 user_requested_size

[kcc]

@alekseyshl can we close this?

[alekseyshl]

Yes, we can