[1/3] wininet/tests: Add tests for overriding host header.

[Marvin]

Hi,

While running your changed tests on Windows, I think I found new failures.
Being a bot and all I'm not very good at pattern recognition, so I might be
wrong, but could you please double-check?
Full results can be found at
https://testbot.winehq.org/JobDetails.pl?Key=14698

Your paranoid android.


=== w7u (32 bit http) ===
http.c:2891: Test failed: HttpSendRequest failed
http.c:2896: Test failed: HttpQueryInfo failed
http.c:2897: Test failed: got status 0, expected 200
http.c:5813: Test failed: HttpAddRequestHeadersA failed 12019
http.c:5819: Test failed: HttpQueryInfoA failed 12019
http.c:5820: Test failed: header missing