[ABI] Updated instruction DB, operands, and minor API changes

This changeset contains an updated instruction database that brings
ARM32 instructions for the first time. It also updates instruction
database tooling especially for ARM64, which will also be used by
ARM32 generator.

Additionally, new operan has been added, which represents a register
list as used by ARM32 instruction set.

Other minor changes are related to ARM - some stuff had to be moved
to a64 namespace from arm namespace as it's incompatible between
32-bit and 64-bit ISA.

src/asmjit/arm/a64assembler.h

@@ -23,7 +23,7 @@ class ASMJIT_VIRTAPI Assembler
 public:
   typedef BaseAssembler Base;
 
-  //! \name Construction / Destruction
+  //! \name Construction & Destruction
   //! \{
 
   ASMJIT_API Assembler(CodeHolder* code = nullptr) noexcept;
@@ -37,9 +37,6 @@ public:
   //! Gets whether the current ARM mode is THUMB (alternative to 32-bit ARM encoding).
   ASMJIT_INLINE_NODEBUG bool isInThumbMode() const noexcept { return _environment.isArchThumb(); }
 
-  //! Gets the current code alignment of the current mode (ARM vs THUMB).
-  ASMJIT_INLINE_NODEBUG uint32_t codeAlignment() const noexcept { return isInThumbMode() ? 2 : 4; }
-
   //! \}
 
   //! \name Emit