<format>: Bogus compiler errors with /presetPadding

[StephanTLavavej]

D:\GitHub\STL\out\build\x64>type meow.cpp

#include <iostream>
#include <format>
using namespace std;

int main() {
    cout << format("I have {} cute {} kittens.\n", 1729, "fluffy");
}

D:\GitHub\STL\out\build\x64>cl /EHsc /nologo /W4 /std:c++20 meow.cpp && meow
meow.cpp
I have 1729 cute fluffy kittens.

D:\GitHub\STL\out\build\x64>cl /nologo /? | findstr presetPadding
/presetPadding[-] zero initialize padding for stack based class types

D:\GitHub\STL\out\build\x64>cl /EHsc /nologo /W4 /std:c++20 /presetPadding meow.cpp && meow
meow.cpp
meow.cpp(6): error C7595: 'std::_Basic_format_string<char,int,const char (&)[7]>::_Basic_format_string': call to immediate function is not a constant expression

The root cause is a compiler bug, VSO-1444086 "consteval + /presetPadding error". Reported by @cdacamar, who has asked us to look into a workaround, and provided:

Note: the workaround is to decorate _Basic_format_string with __declspec(no_init_all) like we do for our validator:

template <DiagMessageSort T, typename... Ts>
class __declspec(no_init_all) MessageValidator