Refactored slightly some constants and operand handling in X86Assembler.
Refactored asmjit::x86 register definitions (now exported as a single symbol).
Refactored bit utilities, now using proper naming like `or_`, `and_`, `andNot`.
Refactored X86RegCount and X86RegMask to support K instead of Fp register.
Refactored X86 instruction table (won't stay for long, new tool to export it is in development).
Renamed instruction group to instruction encoding.
Added XSAVE/OSXSAVE and other CPU features to X86CpuInfo.
Added proper AVX and AVX-512 detection to X86CpuInfo.
Added support to get content of XCR0 in X86CpuInfo (callXGetBV).
Added XSAVE instruction set support (Assembler/Compiler).
Added SSE4a instruction set support (Assembler/Compiler).
Added X86KReg and X86KVar register/variable support (AVX-512).
Added X86ZmmReg and X86ZmmVar register/variable support (AVX-512).