refactor: Remove superfluous inline and register keywords

[bobtista]

• Used clang-tidy

[Caball009]

Are we sure that VC6 treats inline the same way as modern compilers do? I think we've seen in the past that different function inlining can cause mismatches for seemingly obscure reasons.

I'd recommend running this change against a large number of replays.

[bobtista]

VC6 treats inline the same way as modern compilers do

Section 7.1.2: "A function defined within a class definition is an inline function."
C++98 Standard (ISO/IEC 14882:1998)

This means member functions defined inside class bodies are implicitly inline in C++98, regardless of the inline keyword. VC6 claims C++98 support, so it should follow this. How many replays does our CI check with?

[xezon]

If they were not implict inline then it would compile error, because of duplicate symbol definitions.

[xezon]

It also removed register keyword.

[bobtista]

It also removed register keyword.

Yeah, do you want me to keep it? Only 2 lines had the register keyword removed in this branch- both are in the same function Get_Date_From_Day, in:
Core/Tools/matchbot/wlib/xtime.cpp
Core/Tools/mangler/wlib/xtime.cpp

The register keyword is just a hint that the compiler can ignore, even in VC6. It was deprecated in C++11 and removed in C++17, our CppMacros.h defines REGISTER as empty too. It's unrelated I suppose but also harmless. Up to you.

[Caball009]

How many replays does our CI check with?

I assume 9 replays https://github.com/TheSuperHackers/GeneralsReplays/tree/af0c61ccdccbf06750b0ecd2de99fe65842bfc1a