[GR-52567] FFM API support for windows-amd64.

[graalvmbot]

Brings back FFM API support for windows-amd64.

There are two main changes to make that happen:

1. Properly implement the system lookup (i.e. Linker.nativeLinker().defaultLookup()). The problem on Windows is that if the runtime library is ucrtbase.dll, functions like fprintf, fscanf, and all variants of it, are defined as inline functions. In order to make those symbols available for symbol lookups via the FFM API, we need to reference them in C code such that we force the compiler to generate those functions. I've therefore added an array to libchelper (file syslookup.c) which contains function pointers to those inline functions just like JDK does.
2. Avoid generating incorrect reg2reg moves when saving callee-save registers in upcall stubs. We manually save those registers because the low-level upcall stub acts as a bridge between our custom (native) and the Java calling convention. The set of callee-save registers can be different and we cannot rely on the compiler to take care of this. However, we were emitting ReadRegisterNodes accessing all registers with word kind. This lead to the problem that a reg2reg move was emitted, that would move a value between registers of a different register category which triggered an assertion. For some reason, this happened only on Windows but is a potential problem on all other platforms as well.