Support for ClangCL

[HITO]

It can compile with clang-cl but do not because of some macro in optick.h :

if defined(__clang__) || defined(__GNUC__)
#	define OPTICK_GCC (1)
#	if defined(__APPLE_CC__)
#		define OPTICK_OSX (1)
#	elif defined(__linux__)
#		define OPTICK_LINUX (1)
#	elif defined(__FreeBSD__)
#		define OPTICK_FREEBSD (1)
#	endif
#elif defined(_MSC_VER)
#	define OPTICK_MSVC (1)
#	if defined(_DURANGO)
#		define OPTICK_PC (0)
#	else
#		define OPTICK_PC (1)
#endif
#else
#error Compiler not supported
#endif

When clang-cl is used, both __clang__ and _MSC_VER are defined, it's a really small fix, but i think it's worth doing it :D!