[libc++] Don't define operator new/delete when using vcruntime

Fixes build errors on Windows without libc++abi of the form:

    new(173,36):  error: redeclaration of 'operator delete' cannot add 'dllexport' attribute
    _LIBCPP_OVERRIDABLE_FUNC_VIS void  operator delete(void* __p) _NOEXCEPT;
    vcruntime_new.h(87,16):  note: previous declaration is here
    void __CRTDECL operator delete(
    new(205,70):  error: redefinition of 'operator new'
    _LIBCPP_NODISCARD_AFTER_CXX17 inline _LIBCPP_INLINE_VISIBILITY void* operator new  (std::size_t, void* __p) _NOEXCEPT {return __p;}
    vcruntime_new.h(184,28):  note: previous definition is here
        inline void* __CRTDECL operator new(size_t _Size, _Writable_bytes_(_Size) void* _Where) noexcept
    new(206,70):  error: redefinition of 'operator new[]'
    _LIBCPP_NODISCARD_AFTER_CXX17 inline _LIBCPP_INLINE_VISIBILITY void* operator new[](std::size_t, void* __p) _NOEXCEPT {return __p;}
    vcruntime_new.h(199,28):  note: previous definition is here
        inline void* __CRTDECL operator new[](size_t _Size,
    new(207,40):  error: redefinition of 'operator delete'
    inline _LIBCPP_INLINE_VISIBILITY void  operator delete  (void*, void*) _NOEXCEPT {}
    vcruntime_new.h(190,27):  note: previous definition is here
        inline void __CRTDECL operator delete(void*, void*) noexcept
    new(208,40):  error: redefinition of 'operator delete[]'
    inline _LIBCPP_INLINE_VISIBILITY void  operator delete[](void*, void*) _NOEXCEPT {}
    vcruntime_new.h(206,27):  note: previous definition is here
        inline void __CRTDECL operator delete[](void*, void*) noexcept

Differential Revision: https://reviews.llvm.org/D57362

llvm-svn: 352647

0 files changed, 0 insertions, 0 deletions