Detect additional CMake build failures

[falbrechtskirchinger]

Add include_httplib.cc to the main test executable (already done in Makefile), and add include_windows_h.cc to the main test executable on Windows to test if including windows.h conflicts with httplib.h.

Detects breakage fixed in #2057.

[yhirose]

@sum01 @abouvier @jimmy-park @Tachi107 do you have any comment since I am not very miuch familiar to CMake?

[Tachi107]

¯\_(ツ)_/¯

The change looks good, but I don't really care about Windows

[falbrechtskirchinger]

¯_(ツ)_/¯

The change looks good, but I don't really care about Windows

Neither do I, but I've been trained to always parenthesis min and max by repeated issues in nlohmann/json.

Edit: Also, the other change is about detecting ODR violations, which I do care about when I build tests on Linux using CMake. ;-)

[sum01]

It seems fine, but I've never really looked at the project's test cmake stuff anyways.

But isn't it easier to just #define NOMINMAX instead of dealing with those issues anyways?

[falbrechtskirchinger]

It seems fine, but I've never really looked at the project's test cmake stuff anyways.

But isn't it easier to just #define NOMINMAX instead of dealing with those issues anyways?

They have been dealt with previously, so I'm just continuing the practice. And it seems to continuously bite people, as evidenced by the issue trackers.

[yhirose]

Thanks all!