[basic.stc.dynamic]/4 of N3691 says:
The following allocation and deallocation functions (18.6)
are implicitly declared in global scope in each translation unit of a program.
void* operator new(std::size_t);
void* operator new;
void operator delete(void_);
void operator delete;

There are no explicit exception specifications in the declarations.

However, [support.dynamic]/1 says:
Header synopsis

namespace std {
...
void* operator new(std::size_t size);
void* operator new(std::size_t size, const std::nothrow_t&) noexcept;
void operator delete(void* ptr) noexcept;
void operator delete(void* ptr, const std::nothrow_t&) noexcept;
void* operator new[](std::size_t size);
void* operator new[](std::size_t size, const std::nothrow_t&) noexcept;
void operator delete[](void* ptr) noexcept;
void operator delete[](void* ptr, const std::nothrow_t&) noexcept;
void* operator new (std::size_t size, void* ptr) noexcept;
void* operator new[](std::size_t size, void* ptr) noexcept;
void operator delete (void* ptr, void_) noexcept;
void operator delete[](void_ ptr, void*) noexcept;
}

The exception specifications of operator delete/operator delete[] are different.
This inconsistency is probably not by design, since "(18.6)" in [basic.stc.dynamic]/4 links to [support.dynamic] directly without notes about exception specifications.